As long as parents, particularly conservative parents, are willing to subject their kids to this crap, the schools will continue to do it, unabated, as shown here. While I can’t speak for all conservative parents, the ones who I work with make plenty of money to keep their kids out of these hell-holes, but simply cannot resist the fact that the schools are ‘free’ (since they pay the same taxes whether they use them or not).
So...why should the schools change? And why should parents expect them to change?
When parents pull their kids out of public schools, that is how they tell the school system, "You don't do that B$ to my kids!"