Student feedback and jealousy between colleagues
My feeling is that most colleagues just don't care about the feedback. Long before those feedbacks generalized, we already knew who are the good and bad teachers. However, when I was in charge of one year of our engineering program, I tried to move teachers from the lectures where they were poorly graded. It's not easy, but it's do-able. Luckily, it seems uncommon to be globally bad at teaching, so I was always able to find a place for everyone.