I talked to an ex-twitter employee I met in Ireland at bar. He told me very candidly that twitter employees loathed Milo Yiannopolous and were actively trying to figure out any way to ban him. Not a fan of Milo, but there are clearly agendas which can't be extricated from politics.
I imagine a good part of that is because he led a brigade of followers that would go out and harass other users.
there are more right and left-wing fringe users that love to brigade other users.