Genoshs falling is worse than what happened to Wakanda or Atlantis, because when other fictional nations fall they still get back up. Every time. Most of these mutant nations are lucky to last a year. They're not really a part of the franchise status quo ... they're just a part of a particular storyline. And they basically all vanish once that storyline had ended. In the next 3 decades we'll probably get another half dozen mutant nations rise and fall because that seems to be a thing for the x books.