"The man just declared war on the whole planet, his day ends one way [or another]!" "Without warning, Magneto's thrown the planet back centuries!" "Magneto? Really? What did you expect when you tossed him the school?"
Magneto's worldwide EMP pulse or whatever it was surely did kill people, but it also STOPPED THE MILLIONS, POSSIBLY BILLIONS PRIME SENTINELS IN THEIR TRACKS. Without even killing them! Y'know, the mind-controlled cyborgs that were currently, ACTIVELY, RIGHT THIS SECOND trying to genocide or enslave all mutants??? The ones even you x-men were completely failing to stop???
Fuck you all, Summers. You too, Logan.
Magneto was doing a damned fine job of growing into a new, less homicidal role, and the only reason you have time to stand around planning and whining about it now is because Magneto BOUGHT YOU THIS TIME.
And also bought time for every other mutant, most of whom are far less able to defend themselves, to at least TRY and hide. You guys couldn't even protect yourselves, much less all the other mutants in the world!
Maybe consider that he might not be acting purely to piss off the x-men, assholes.