-She gets rid of all the mutants with any future sight (seemed to only be Idyll) since any warnings of doom brought unrest and she was super arrogant
-She aggressively bred strong mutants, and makes note the many behind the wall never knew of the world beyond, and therefore remained ignorant, despite being safe
Granted Krakoa's not totally in the same spot, but it sounds familiar.
White Sword (who can ressurect people) and his army fought and died and came back so many times they lost their minds