mentsch, I don’t think people were actually claiming the Chassidim should have gone to Public School chas v’shalom. Usually the people in the CR being critical of frum schools are those who advocate for more MO Day School systems.
It’s just an age-old CR debate. One side thinks it’s worth taking on a little bit more risk of kids going off the derech in order to pursue a better education for them. The other side disagrees.