Which is why they are pretty much universally funded by religious fundamentalists who spent their past years trying to force textbook writers to deny climate change or evolution as basic scientific facts.
This isn't disillusioned people looking to tear it all down and rebuild a wonderful new system, unless you think Betsy Devos is some sort of anarchist. These people have very specific complaints about the school system that rarely have to do with the actual problems of actual outcomes, because the people who by and large ARE getting actual bad outcomes from the public school system don't really have a voice.