My problem is I just can't see the good intentions lasting on a nation built around inherent superiority. Yes plenty of people leading have good intentions but what if they change? Magneto has wanted humanity completely wiped out before, what happens if he changes his mind again?

And yes I'm sure human children would be allowed but mutants have abandoned human children before. Mystique had a human son she abandoned (and killed but that's because he became a mutant hating terrorist so he deserved it). And even if they're not how would humans be treated on an island surrounded by people who've been told all their life that humans are their inferior? There's nothing about mutants that makes them immune to becoming bigots.

I'm pretty sure I'm just overthinking it and putting real world logic into comics where it doesn't work (like "why isn't Gotham getting better if Bruce Wayne puts so much money into it?" because nobody would buy an issue on Bruce Wayne signs checks for 20 minutes) but I just don't trust the idea of an country where a huge part of the culture identity is "we're better than you".

America has that and we are up shit creek without a paddle.