That's crazy, and I'm sure there are schools who just don't put a priority on athletics, and it starts from the top. Now I can't address the coach who let a kid shoot a granny FT behind his head, but if all the "serious" ball players just quit, then that's what you're left with. Programs are built way before high school. You get a good group of serious ball players and start grooming them from the 3rd/ 4th grade on up, and do that year after year, the goofballs are not around come high school. If a coach has limited numbers of players, the ability to move away from them is taken away.
As far as college, different animal. Most kids are going to either go to a school who hopefully fits them academically ( yea, I know that's a foreign concept in 2023) but sure the coach matters. But THAT's totally different.
I my mind, I just cannot imaging sitting out my high school days because of the coach? You'd rather NOT PLAY than play for a coach you don't like??? That just seems odd to me.