Did you know that one reason we constantly test our school children is because of a lack of school choice?
Think about it: If your grocery store were doing a poor job, you wouldn't need to test its employees or produce to find out. The store would simply lose customers. We know which businesses do a good job because we have a choice and can observe consumer behavior.
This process completely breaks down for education. If schools are doing a poor job, parents have to pay twice to switch to a better provideronce in private tuition and again in taxes for the government schools, even though they're no longer using them.
This is like paying our regular bill at one store so we can pay a second bill at a better store. Most people would be forced to stay at the first store, but they'd always wonder if they were getting their money's worth. This is one reason why we test our school children till they're cross-eyed: We can't tell from consumer behavior whether our schools are actually teaching them anything.
School choice would change that. Maybe that's why the education establishment is so scared of it.