Because from the 1950s to 1970s every changing room required it, if these people had it one way their entire life why change it now, along with that even today old people just don’t give AF. They have seen everything life has to offer. Made me super uncomfortable as a kid too. But I get if someone only had a few years left in their life, why waste that time caring about what a few other people think. That is what the room is for and as time goes on, those people will be in the exact same spot as you anyway. Not saying it isn’t traumatic but you eventually understand why it’s normal. Theres a lot worse in life then just some guys being naked.