Right. If terrorism can be outlawed even if your religion mandates it, then the obvious next step is that Shabbos can be outlawed since it causes people to work less, hence pay less taxes.
You see, reasoning like yours is precisely the reason why the very alert Rabbonim are trying to nip this pattern in the bud. Technically it doesn’t bother anyone if the parents will sign a document. Nobody is forced to do it in the first place. However, we actually don’t think it is dangerous in the least when appropriate precautions are taken (and they are), and we don’t want to be forced to say that it is.
You bring up two distinct arguments. One does not help the other.