I don't know really - perhaps the Puritanical thing feeds into greater consciousness about bodies and nudity? It's like, in Britain, it's generally considered to be little more than a loo and no-one generally cares too much who's in there!!!!
True story - I went in the ladies when (ostensibly) dressed as male in a bar. I was drunk and the sink was broken in the men's. As in completely broken!! There wasn't a functioning tap and no soap. So I went into the ladies to wash my hands. I had a brief chat with the girl at the sink about it and she didn't actually care.
Same goes for another situation where the cubicle in the men's was occupied by two men!!

They invited me in and I was like "OMG no!!". I still needed a wee, and with that going on I ran into the ladies and used that. One girl in there looked sideways; I explained why and she thought it was really funny. Looking back now, it was.
Now I tend to go out appropriately dressed, no-one even questions it. Why must America be so weird about a silly little issue?

I go in there to carry out some basic needs, wash my hands and maybe sort my face out. That's about it. If I was a pervert, I'd at least have a hidden camera or something!! Not a pink Polaroid from Argos filled with pictures of friends and random selfies.

It might rain a lot here, and some of us are a bit miserable, but we get certain things right in this country xx