Not because of this, but because they were run by lunatics.
I can't imagine why any white parent would put their kids in public schools now, other than normalcy bias, or that they just love the material crap they can buy themselves for the cost of private school tuition.
Our first was in good schools with some elderly teachers that knew how to teach real academic subjects and got Latin through high school. The other three were alternately parochial schooled and home schooled. I remember the difference from my own private (US government paid for) Calvert System school in Istanbul and the school I later went to in the USA. In fifth grade I was so far ahead of everyone else that I did not have to study any of the stuff that was in the curriculum until High School in a high school that had, again, some ancient teachers who were teaching as if it were thirty years ago. I got a now college level Physiology course in 11th grade and a chemistry class the same.