But surely you can recognize the difference between simply teaching your child an evidence-dry religious worldview, and teaching them to actively hate and murder people or break laws that would endanger others?

I agree, within reason is always necessary, and if those things were being taught then it's time for a visit from CPS, for sure. But it still feels like a potential slippery slope of "You're abusing this child by teaching them things that aren't approved by the state" in the extreme case. I know that may sound silly, but with as polarized as the country has been recently, and with authoritarianism on the rise worldwide (I saw a man get arrested in the UK yesterday because he criticized some protests on Facebook!), I don't see it being an entirely foreign idea.