There's no question that there's all kinds of problems with public (and private) schools. And conceptually there's no reason why foundations are inherently bad.

There's no question that there's all kinds of problems with public (and private) schools. And conceptually there's no reason why foundations are inherently bad. The issue though is that in practice they are mostly doing really bad things -- standardized testing, value-added assessment of teachers, charter schools, merit pay, etc. And of those, standardized testing and charter schools aren't even inherently bad either, it's just that again their implementations are extraordinary bad and damaging in practice.