Last time I checked Mutant Growth Hormone was allowing any and every dick head with a couple of hundred bucks to shoot cosmic fire out his arse anytime he might have a mind to.

The Homo Superior stuff is kind of funny. In a world of six billion there were two million mutants and supposedly a crap load of "latent" mutations watiting for a toaster accident or a near death experience to set 'em off. Overall the normal boring bunch seems to be handily out breeding the special ones and the special ones are themselves the descendents of the normals so it all seems pretty unlikely that the "next step" in evolution is going on. Heck we supposedly outbred the Eternals, the Deviants, the Inhumans and whatever other offshoots came along. Why should we see mutants as any different? One day they'll leave earth and a new crop of freaks will pop up and bounce around between chosen few and pariah status until THEY take off.

Mutants in the Marvel Universe represent a small minority -- we used to calculate one in a million, when I was working on UNCANNY -- but that does not mean their kind are automatically excluded from winning this particular lottery.

"homo superior"

Nazis or really hardcore christians?
..oh, mutants, sorry, that's alright then..

I think both mutant and "irradiated" superheroes would probably be looked upon with scorn and distrust in the "real" world, particularly if they looked in anyway "different."  Whether Nightcrawler was a mutant or achieved his blue skin and tail in a bizarre accident involving a threshing machine, he would still be met with discomfort and fear.  Handsome mutants and handsome heroes would have an advantage.  Superman, an alien from another planet, still looks like "one of us" and thus he would be more accepted.  The Silver Surfer (or the Martian Manhunter or any other "different looking alien") is also an alien from another planet, but people are never going to look at him anything like they look at Superman.  I know there are other reasons, like dour disposition, but the big picture is still the same.  Appearance matters quite a bit.

That said, I do agree to some extent with JB's point that people who weren't born "that way" but were changed thru random fate would have a small advantage in the eyes of the general public.  However, I still think many / most would be distrustful, solely based on appearances more than anything else.  Batman is a handsome devil as Bruce Wayne, but I think most people on the real planet Earth would be scared to death and forever untrusting of him if they ever saw him in dark cape and cowl.  Almost any masked hero would probably face an uphill battle for that reason.

Or Europeans? "

- Or americans?
I'm not as 'not american' as one might assume, though I do live in Sweden currently..so I'm not one of those ''europeans' who go after america at every turn.