The whole think of the children! argument is just a laughably thinly veiled way of being transphobic (a term that I feel gets thrown around a lot, but definitely applies in this case). Like first of all how many potential rapists, predators, pedophiles, etc, are gonna go, Time to go rape somebody in the women's bathroom! Oh wait, I'm not allowed in there, shucks, foiled again! None, that's how many. If someone is planning on committing a crime like that a law saying they can't go into an unmonitored public place isn't going to stop them.