It's the X-Men's premise (nor, for that matter, does Morrison's exploration of mutant culture require it to be discarded; there just needs to be enough mutants, something that they're s-l-o-w-l-y working towards.
Except that they HAVEN'T been working toward a better future, slowly or otherwise - except for the Morrison era, EVERYTHING has ALWAYS gotten worse for mutants, to the point that "Days of Future Past," which was once the WORST case scenario, now seems like the BEST possible alternative. THAT'S the Claremont dynamic, and that's WHY it needs to be shitcanned. FUCK the purple-prose melodramatics of the team's relationships taking up 90 percent of the panel time, and leaving behind only 10 percent of the stories for the social critique that the X-Men congratulates itself on being about. FUCK every retcon which tries to turn Xavier into more and more of a creepy fascist fucker to make him more "realistic," and FUCK the fact that so many of their plots - like those of most non-mutant superheroes nowadays - revolve around almost all of the characters carrying Idiot Balls. If all that the X-Men can do is ape a Claremont-esque flavor of emo soap operas, then the franchise just needs to fucking DIE.