No. Even if it makes no logical sense, they still may have religious reasons for it, and confiscating the kids because of that would interfere with Freedom of Religion. I understand a government that isn't all-powerful is a foreign concept to this forum, but people still have their rights. Children aren't the property of muh guvment, and this very idea that they can force parents to put something in their kid's bodies is sickening.
I agree with you on this point mostly, but I am curious: how do you feel about requiring chemotherapy for child cancer patients when the parents' religious beliefs don't allow so. I feel like the government needs to defend that child's right to live when the parents are impeding that.
Also, I'd be surprised if this has to do with religious reasons - I saw a map the other day that confirmed my suspicion in that Oregon was the national leader in opt-outs and the south mostly lagged behind.