I'm very involved with my teens school work as well as their school. I have very high standards for my teens and even higher ones for their teachers.
What really grinds my gears is, When a teacher has a race issue.
I meet with my children teachers and have a parent to teacher talk. I let them know " you don't have to like my child, but you do have to teach them. and I mean give them the best you have to offer as a educated professional.