These teachers need to be reminded of exactly who they work for. As it is, they are paid with money that is taken from citizens, under threat of force, whether they have kids in school or not. There's no choice - just try not paying your property taxes and see what happens. If teachers want a raise, then more money has to be taken from the people. If that happens, they get their raise without any performance expectations.
It would be better if parents paid the schools. With charities paying for schools in really poor areas. Every parent with a child in that school becomes that school’s governing body, and representatives can be elected every couple years to run the thing, with hired permanent staff helping. Government as middleman just doesn’t work so well. Ever, really.