From an European perspective, I would say that American people have very rigid gender roles. As if they were afraid that if they straight out said or do something outside those roles, then society would collapse or something (pun intended). Or that it is imposible to deviate from those norms or something.

Maybe have to do with their idea about what is “natural” even if it is a social construct. Anyway, if they fret about speedos, I don’t know what they would do with topless or nudism. XDDD