I have seen women go topless for no reason NOT during the gay pride parade or working for a strip club. A certain neighbour of mine LOVES to use her right during the summer on early morning jogs. My neighbourhood doesnt have many kids (though it has two schools) so nobody minds. Except the really catholic family, but they just shut up and turn the other way.
I'm guessing she's not particularly top-heavy?
Anyway, it's a social more, and it does affect other people, so while I'm not opposed to allowing public nudity, I can see how it is a legitimate law.