Because it's all about them.  Leaving their mark on the characters, changing their looks, attitude, and character to fit who other people think they should be, not who they were created to be.  Easier to make the character into who you want them to be than write them around who they should be.

From what I've read online (little) and seen in the books (even less), most writers just threw obstacles in their path that usually led to death, resurrection or a complete change of the characters mentally and/or physically.  There was no status quo, no putting the toys back where they found them by the time the writers left. 

Of course, all of Marvel is like that now...

QUOTE: I'd like to see what Alan Davis would do if he were allowed to pick up where JB ended...

That would certainly be interesting, but the creative team I'd go with first, short of JB himself, would be Roger Stern and Kerry Gammill.

For one thing, they're a team that's not a team. You basically get to see what happens in their lives as they intersect occassionally and stand together (briefly). But for the most part, ALPHA FLIGHT was unique in that it was essentially about the characters and their personal endeavors and demons, while not beating the reader over the head with overwrought melodrama.

The way to write AF is to write about the characters as if they aren't in a team at all.