A reader writes:
I have always theorized that older men were so much more comfortable with nudity because they were all in the military at some point and are just used to it. They also grew up in a time where it was not instantly assumed that two men naked in the same space must be gay for each other. I'm 34, gay, and have spent plenty of time naked in locker rooms (steam rooms, saunas, hot tubs, etc) and analyzing what I felt to be bizarre behavior. I personally have no body shame and get naked as often as possible, but yeah, frequently the younger guys seem to be a little more inhibited than the older guys.
An older guy writes:
When I go to the gym at the university where I work (age 63), I proudly walk around naked because that is the way it is. The reason "old men" are always naked in the locker room is because when we grew up ('50s, '60s, and '70s), that was the only way you could be in a locker room for gym or sports. I don't know how it is now, but there were a few rows of lockers and gang showers. If you had attempted to cover yourself in the locker room you would have been stripped and probably had some deep heat rubbed on your balls.
The young guys seem to grasp, but frankly I think they are afraid that people are secretly comparing dick sizes or something. It is true, we did that in 6th grade (1960), but not since then, or at least I haven't. It occurs to me that we may be seeing a gradual migration from a less-conscious sexuality expressed by Whitman in Leaves of Grass to the hyper-sexualized 21st century where everybody needs to have some kind of sexual marker staked out.
Not sure if you've had a chance to revisit the post, but the torrent of comments from your readers adds up to something spectacular and hilarious. Check it. Dominant theory seems to be that the shift away from a norm of showering at school amped up body shame something awful.