I shared an office with a fellow like this for six years, until he retired. He had was a rant every day. Everything about school life that wasn't the classroom or his after school tutorial was a pointless distraction--sports, shows, special assemblies, pep rallies, clubs. Everything was a conspiracy against education--classroom group work, technology, the observation rubric the Board of Ed adopted, Common Core, the textbook of his supervisor's choice. Any minor criticism of his teaching (he was an excellent teacher, but sometimes observers are looking for something you don't believe in doing) was an attempt to force him out, since he was a senior faculty member with a high salary. I never did come up with a solution to get him to shut up. All I did was say "Uh huh" in as bored a tone as possible until he wound down. Since I wasn't his supervisor, I couldn't very well talk about his effect on the rest of the team.