I think it has more to do with, as you said, wresting control of education away from the local community, and also the demonization of Christianity. It has been a shock to me that secular persons of Jewish descent have been so prominent in their lawsuits against Christian expression in schools, given the experiences I had with Jewish/Christian benevolent co-existence in our school.
Like I said, I attribute it to both. Local control for local community standards is the right way to go, in my humble internet opinion. Test the basic knowledge, critical skills, but put the local community standards in place. I know that flies in the face of our ‘globalized economy’, but my guess is most people don’t like being lied to, want to trust someone who gives them their word, doesn’t like to be stolen from, beat up, attacked, called names, want to help their neighbors, or be helped by their neighbors.