Identity Crisis was completely mercenary, an attempt to show that DC could do
Marvel simply felt there were too many mutants, so their solution was for one of their characters to have a "Britney-shaves-her-head" level meltdown (doncha just love that mental illness is simply a plot device and a lapse of reason instead of a real problem?) and basically commit genocide. And it wasn't because the creative teams had run out of gas, it was because editorial wanted stories to focus on something other than the sprawling mutant population.
(Side note: there is speculation that the editorial edict was a kneejerk reaction to Grant Morrison's tenure on the book. Traditionally, the mutant books have been metaphors for minorities trying to survive in the world, where they can risk their necks for the norms' sake and the norms will still hate and fear them, and trying to find nobility and purpose for themselves that society at large denies them. Morrison actually took the "mutants are the next step of human evolution" thing and ran with it, creating a literal rising of the mutants and a real sense of paranoia and fear in the general populous. Then Morrison went to DC and Marvel went about trying to revert the X books to how they were thematically before Morrison's run, with the norms simply exclusionary instead of reacting to a building threat. Don't know if I buy it, but it fit damn good.)
And people like me just waited, knowing this would eventually reverse.
Well, apparently, it's happening now. With the Curse Of The Mutants storyline getting underway, things seem to be shifting to at least restoring lots of the mutants out there and putting the numbers back up. Proof? In the comic shop, there's a book called, Namor -- The First Mutant. I asked, Since when? The guy behind the counter who is reasonably versed in Marvel history said, technically, Namor is a halfbreed and other stuff, but it basically boils down to, "Why? Fuck you, that's why!"
Of course, this really does nothing to make me want to start following the books again (although I do wonder how this is going to affect the little corner of the Marvel Universe X Factor occupies). So what if the characters are more like they were? They are still being changed at an editorial whim, disregarding any emotional investment in the stories just because. Even Ralph Bakshi knew when to reel it in -- while The New Adventures Of Mighty Mouse was breaking every convention the cartoons established, it never broke history (Mighty's Wedlock Whimsy, according to legend, was created because the staff wanted to see what they would do if they backed themselves into a corner. Mighty was going to marry Pearl Pureheart. Can't do that, you'll change the character forever. Bakshi and his staff preserved the character without losing a step in their comedy and creativity. The episode was a massive put-on, and people like me still had a gas with the intentional cop-out ending). I have no faith that characters I enjoy will be allowed to remain as I enjoy them because someone might decide to do their own thing with them based on their whim instead of trying to tell a good story.
So, the mutants will be back. I, however, won't be.