Teachers are the scapegoats of the oppressing society we live in, just like parents. Teachers have quite limited freedom to do as they would like to do. I believe teachers know this by heart, but they aren't given this information and thus they struggle to do their job as they are told hoping to do at least something right. Teachers are oppressed. They do as good a job as they possibly can and they should by no means be blamed.
Teachers are good people who are raised by the oppressive society.
Some have grown out of the oppression but most haven't, and it's not their fault. The only way to make some real changes in the schools is to support teachers, form support groups and break the traditional isolation that is so too damn common among teachers. As much as most of us have hated and still hate the schools, we shouldn't pour all our hatered upon the teachers, because that's the most unappropriate target we can find. You don't attack an idea by attacking people. That's where inquisitions and purges always fail.