So, he’s stirred the pot over and over, including bringing in people who’s main claim to fame is grievance, but he still had a job at the university, and he quit, for amongst other things, too much grievance.

I’m not sure that this proves it’s the university that’s intolerant (although I’m sure some faculty and staff are). Or that he’s capable of enough self-reflection that he should be teaching reflection to others.

Plenty of blame to go around. Resignation letters are attempts to write history, but as he himself should be teaching, there are surely differing views here.