Undermining a relationship to get your way
That's what comes of using money to make a political point with a grown child.
Not paying for non-performance is legit.
Not paying for a poor school is legit.
Not paying because one doesn't like the politics of some of the school's denizens is disrespectful of the "child's" ability to reason as an adult, and incidentally reflects a lack of confidence in one's own efforts to influence the child except through economic force. This is not elementary school.