Carl M. Cannon, writing for RealClearPolitics, chronicles the abuses which the university tenure system engenders. Take it from someone who spent his working life in universities, such abuses are real. To the stunners Cannon describes, let me add a few from my experience.
The College of Business in which I spent most of my professorial career had a professor who was supposed to teach the mathematics of business but in fact spent most of his class time pushing nuclear disarmament. We had another who was so scathing in his in-class denunciation of students that he often taught classes with fewer than 5 enrolled, and failed most of those. We had a third who, as a minority, traded on that fact to be on leave at least as often as he was on campus teaching.
At another campus a colleague ate his lunch at his desk and dumped the leftovers in the trash can. This attracted mice and/or rats for which he ended up putting d-Con baits in the corners. His office was so filthy and littered I refused to enter.
A faculty member at the other DrC's doctoral campus offered to be her dissertation advisor if she'd be his mistress, this after he had met me. The other DrC later met his wife at a professional meeting and that lady asked if her husband had hit on her.
A fellow doctoral student who went into consulting instead of academia asked me later, "How do you put up with the strange colleagues?" I responded that he had identified the major drawback of an otherwise great career.
I'm not anti-tenure but it certainly does get abused by people who should know better. I only started this somewhat political blog after I retired and knew I would not look for another faculty post.