I think public nudity, at least for men, regardless of reason is on a rapid decline. I think younger generations of men are increasingly being told from the youngest age that there may be something wrong with their body. Something is not perfect or is different and this is a problem.
I think men are effected by this harder than women because there is such diversity in our private anatomy. For women, they may have large or smaller breasts but it is abundantly obvious looking at them clothed. For men, ours is not so apparent, so it is easier to hide what we have. Given, that many men may be uncomfortable or insecure about their sexual anatomy, why would they be willing to be nude infront of others?
Anyways, I think communal showers in gyms, suanas, nude beaches and things that involve male nudity are going to slowly dissapear in many parts of the United States, in the future.
I know I have a lot of generalizations, but that is my little sociological theory.
Bodies are more imperfect than they were in earlier times. As we all know, there is an epidemic of obesity. I wonder if that's a factor.
Until at least the middle to late 1970s, the downtown YMCA in Minneapolis did not permit men to wear bathing suits in the swimming pool unless women were present. If fact, if a man walked in wearing a bathing suit, he was directed to remove it. Now it appears that it is exactly the opposite, although I haven't been to the Minneapolis YMCA since 1978.
Here at one of the YMCAs in Albuquerque, there is a glass wall between the pool and the weight room. Obviously bathing suits are required.
I mentioned this in another thread, so I hope that it is still acceptable to mention it here also. On a motorcycle web site, there was a thread about child sexual abuse. The consensus was that "ordering" kids to strip in physical education classes made them more vulnerable to child abuse because then it would be easier for a predator to get them to strip. In fact, they even saw it as abusive to "order" kids to strip in gym classes. They were unable to understand that they were not ORDERED to strip, but rather, that it was simply a custom that was generally accepted by everyone without question.
When I lived in San Diego (1978 - 1994), I often went to a large nude beach. On weekends, there were often thousands of nude people there. Nudity was made illegal there about 1977, but the law was generally ignored except on the city portion of the beach where the police would sometimes enforce the law. On the state-owned portion, the policy was not to enforce the law unless there was a complaint, in which case nude people were directed to cover up and there were no charges unless they refused to cover up. So, it remained nude in spite of the law. I'd be interested in learning what the current situation is there.