What brings you to that conclusion?

Churches that teach children things with which I agree are imparting liberality, wisdom, truth, goodness.

Churches that teach children things with which I disagree are doing brainwashing.

Not all religions are the same. Some religions make a lot of sense. Even fundamentalist religions have a few good points. If the parents are steeped in that religion I would just say that I think they are mistaken but that they are doing what seems right for themselves and their children.

I think most people teach their kids the right way to live in this world the best they can.