The problem with giving parents the absolute right to control their childrens' input of memes until the children are too old and stupid to learn anything new, is that it creates generational propagation of obsolete ideologies. All the Dole children think exactly like Bob. All the Hitler children think exactly like Adolf. Same for the Mengele children, the Nixon children, the Stalin children, the Netanyahu children, etc...
The same can be said of the children of the more politically correct. My opinion is that religion is a waste of time and resources, and therefore, those who force their children to be religious is doing precisely the same harm you allude to. That is strictly MY opinion. If there are enough of me around, should we be allowed to force the government to take children away from their religious parents? More mildly, can the government "protect" a child from religious ideas? What gives the society more rights to regulate how the child shall be brought up, except the narrow interest of protecting the physical safety of the child? It is not even clear that the government may force a child to accept secular ideas that may violate the child's religious background, even if the government has a compelling secular interest in doing so. Yes, we would like fewer Hitler's in the future. But should we NOT let the people decide how the raise their children because there is some risk of a few of them turning into future Hitlers? Ern