Ted, I am right with you. The art on those is top-notch. I also liked the very ending of the Flash series (altered face plot convolutions aside.) Really, they could have just left him in the 30th Century, but that's just not headline-grabbing enough. And it would have left Barry around, giving his fans a constant rallying point while DC tried to get Wally's run going. 

Dave, as I recall from some interview way back when, the creative team on the Flash heard about the character's death months ahead of his impending death in Crisis, right around the time they were planning to wrap up the Trial, which by then had already gone on for a while. Rather than come up with a new plot line for the next year or so for a character without a future, they simply punted the plot reveals for the end of Trial down the road and kept beating that winded ol' nag around the track a few more times.

For a certain generation of fans, a good deal of DC's credibility lay in the deaths of Barry, Kara, and later, Hal and Oliver. Once that generation was determined to have moved off-center and the new one coming in was seen as their core audience, DC's current editorial team in no way felt beholden by the pronouncements and promises made by their predecessors. If an argument could made that the "Return!!" of these characters delivered higher sales than their continued absence, well, then it would have been irresponsible NOT to kick those numbers up and resurrect them. 

I was never a Wally fan, but holy cow, I would feel disrespected right now if I were. I liked him as a Titan back in the day and up through the Wolfman/Perez years, for the most part, but once Mike Baron altered his set-up, his dad became a Manhunter, and his marriage and kids became key components of the character, I was out. I didn't hate it, but I also was not interested. I didn't quite buy any of it. It all seemed forced and artificial.

On a certain level, I preferred Barry, sure, but I wasn't "protesting" Wally. I just didn't like him as much. Much the same is true of Danny Ketch. Just... not my guy. If he's your's, hey, more power to you. My investment level just wasn't that high. Nothing about Midnight Sons, or shotguns that blast hellfire, or any of it grabbed me. Was I reluctant to commit, having been "burned" before? Maybe. Or maybe the corporate behind-the-scenes shenanigans had finally drawn too much attention to themselves and the product no longer seemed anything but arbitrary and haphazardly rendered anymore.

In any case, Wally's current state highlights why editorial edicts are no less whims than anything else the industry does. Wally was announced as the Flash. He became that, and for years and years DC wrote the book as a next chapter in an ongoing saga. The page had turned. Wally had to fight the ghost over his shoulder and constantly work to establish himself as the Flash, in his own mind, if not in the minds of everyone else. That was their moneymaker. That's where the story lay. Things had moved forward. Except...

No. No page turned. No story advancement. Everything is written in sidewalk chalk and the rain is constantly coming down. It's all reboots, reset buttons, and the new team's personal biases and proclivities making the rules now. This one clown at the top makes it known he doesn't like a character, and everyone rushes to cap the character in the knees to get the boss's approval. 

This sort of thing happens in every industry, yes, but it's particularly onerous in this one because the product being mangled in the process is storytelling. And there is no good story anywhere that continually stops and restarts itself, trying to sell the audience on the idea that this newest restart, this latest iteration is the One That Really Matters! Accept No Substitutes! Everything Else Was Just the Warm-Up Act For... THIS!!!

Yeah, films and sequels and such*, but those don't work well and I don't know anyone who buys the idea that Prometheus and Covenant have cleared anything up or revealed great hidden truths in the Alien Saga. Those who like them tell you in was a good time spent in the theater. How it all fits together and hangs as an overall tapestry, eh... those are secondary considerations at best. Was this film any good? If so, yay. If not, oh, well...

Comics ridiculously try to have their cake and eat it too by keeping everything in place but off to the side until it's needed again. Much of that clutter is hated by the new guys and they strip-mine it with cruel intent or spit in the face of it when they can. Some wish to preserve every jot and tittle and bring elements back to fascinate the newcomers. However it's done, it's always One Big Story. Even the new stuff brings cartloads of the old with it when it restarts, so we don't lose the things we Like in our haste to discard those we Don't. We're told that it all ties together, boys and girls. Sometimes with spit and bailing wire, but everything fits. Everything's connected.

So we start and stop and go back and go forward; we lurch about each time we shift gears and no one enjoys the ride very much. In among the constant sense of whiplash and lack of forward momentum, we get guys who will drive the vehicle miles out of its way to run over some particularly rough patch in the road they see as needing to be leveled out. And Dan Didio rather mono-maniacally sees Wally as something that needs to get flattened. A lot. So much so that it is weird.

Now if the corporate wheel of power spins and somehow places Mark Waid at the top of DC, well, that will all change. Wally will be given a new place in the pantheon and be well-respected. For a little while. Until the next spin. Who will Waid choose instead to drive over in the ramshackle bus we're all stuck riding? Who knows? But when the vehicle lurches and stops and backs up and shifts sideways in order to run them over, we'll all be thrown about and made uncomfortable by that agenda. And the one after that by whoever comes next. 

Editorial edicts are in force for as long as the editor is announcing them, and sometimes not even that long. It's all written in sand on a beach with some ridiculously fast-moving tides.

* When the James Bond franchise does a stop and start, beginning over again, strangely now with Judi Dench at both ends of his career (the "M" stands for "Moebius strip,") it doesn't take "Gone With the Wind," "Chronicles of Riddick," and "Remains of the Day" down with it. A new start for Chucky, Freddy, or the Terminator doesn't erase the Star Wars prequels (would that they could.) We're not left wondering which version of "Little Women" syncs up with which Sherlock Holmes adaptation. Comics' bizarrely overarching inter-connectivity makes the whole "double-clutching into infinity routine" unwieldy at best. 

To start at the end first... movies and novels and even TV shows are rarely so intertwined that chasing one will change several others, as you noted. And these properties sometimes even seem to ignore existing stories to tell THEIR stories with the properties.*

And it seems even those intertwined stories don't give a shit about their fellow properties. Star Trek got rebooted via a movie, and the writer and/or director didn't understand that changing one moment in the past - in that new alternate reality - can't just ignore things that occurred prior to that change. And two more movies and a limited access TV show don't make up for that. 

Marvel movies had the tie-in to Marvel's Agents of S.H.I.E.L.D... not a lot, but there was no question on the TV show that it was definitely part of the MCU. But Netflix didn't much care.... I THINK I recall one mention of the Chitauri invasion in Daredevil, but only that one. So... did that show invalidate the Daredevil movie, or vice versa? 'Cause I can damn sure testify that Michael Clarke Duncan and Vincent D'onofrio were NOT the same character. Now, top this that AoS tied into Infinity War... but seemingly ignored it after Endgame. I've read a lot that AoS is now its own reality, separate from the Avengers... but I've seen nothing on the show to imply this, and AoS certainly WAS tied in. There's a change that I hate. Unless you want to tell me that every single agent was missed by Thanos' snap.

That's for movie tie ins. As for the comics... consider this assemblage:

Aquaman. Batman. Flash. Green Lantern. Manhunter from Mars. Superman. Wonder Woman. Yes, they were the original Justice League. And EVERY ONE OF THEM DIED. Oh, sure, they were brought back one way or another. They were brought back, sure. But I can only think of one of those characters that died to make a good story and continue the storyline.** Otherwise, it was just an event. Yes, surely, the point of these books is to sell, and events do this. But those deaths seem kinda gratuitous, and I can't even hate those "changes"... because they're undone and we know that they will be.

**When Mr. Byrne killed Wonder Woman, it directly impacted her ongoing story, and was so smooth in that storyline that I almost cheered for her death. Um, well, almost. But it wasn't an event for an event's sake... it was for a great story. Damn, I would love to see the John Byrne Wonder Woman collection.

Of course, that list is hardly limited to the original Justice League, but it's an example of how these changes occur, only to be un-chaged. It's even worse at Marvel, because those characters die and come back... and I'm not sure if any notice is taken in any other book. If Spider-Man Captain America, or the Fantastic Four were killed, I imagine that the papers would be loaded with those stories, and they would carry over to everyone's book... Cap is DEAD?

What's that, in the back? You can't just change another story simply because a character died in his book? Interesting point. My reply is A) Marvel and DC have interrupted PLENTY of stories for big events (or pseudo events.) Can't imagine that this would be the exception. B) If an event doesn't affect anyone else, maybe it shouldn't be done. If Daredevil never notices that the FF were murdered, maybe murdering the FF was the problem.

The other changes I hate are those caused by Crises. Or Secret Wars. But reboots/great change crossovers in any case. It especially enrages me in that every one of these seems to end up with a "heroes vs villains" big fight. And every one of them seems to demand crossover stories that interfere with ongoing storylines... none that seriously change anything, but that have to be crammed in. Sometimes with ridiculous climaxes. ("Take away my sight again, or I'll sue you.")

Worse... an established change that did work for people*** gets undone, and that's seems mostly at DC. As Brian H. noted... who's the Flash? Wally West, of course; it happened after Barry Allen died. Oh, no, sorry; Barry is back and Wally is off to limbo. Ditto for Hal Jordan and Kyle Rayner. Or Ray Palmer and Ryan Choi. It's not as if a setup with a new character taking over the original role for a few months, and then the hero comes back, supplanting the new hero. I'm minded to think of the big Death of Superman story, where Steel and Superboy tried to step up, only to get pushed to the back pages when Superman came back (luckily for them, they were popular enough to get their own books. But even so, if one looks at what's been twisted in Superboy's story, one can't tell what changes are good, bad, or only temporary.)

***I do not like most of the crisis series, myself. But I'm barely people anyhow.

Mr. Hague is right; changes no matter last because there is no single editorial overhead to say, "This is the change and it's STAYING this way." Too much of this is just painful.

*As the wise Mr. Byrne has noted, the entertainment business as such should always be about "How can I tell Captain Fonebone stories" not "How can I tell my stories using Captain Fonebone."