Communal Shower debate

Today I went to the swimming pool as I do about twice a week. I took a shower in a communal area before and after and when I got home I started thinking about how this doesn't happen in the US that much. My question today is why not? What is the reason that people are afraid to take showers in a public area where only members of the same sex are present?

My first thought when trying to understand this phobia from a male perspective would be to assume that many men are rather uncomfortable about their sexuality, and/or they have the assumption that were they to shower in the presence of other men they would become targets of a pick-up attempt. This seems over simplistic however and childish. First off I doubt many gay men go to communal showers and attempt to pick up men they think are straight anyway. Secondly this falls into the mental trap that many straight men have in their perception of homosexuals: that everyone who is gay wants them. Wake up and smell the coffee, they probably aren't interested.

My second big thought about all this is that there is some phobia about exposing one's body to someone else. The underlying idea here is that a person is extremely self conscious about their body and therefore unwilling to put it up for scrutiny. The odd thing about this however is how little people actually wear at a beach on the other hand. My thought on this, as someone who has used communal showers all his life and never found it odd, is that people don't use communal showers for sizing each other up. A shower serves a purpose: to get clean and I doubt anyone stands around looking at each other. I am going to guess that the recent generations obsession with penis size might also be a part of this. If this is part of the problem then I am going to go ahead and say that it is the most irrational reason for not using a shower.

In the end I think that having been raised in a culture that didn't have a problem with communal nudity is probably a part of the puzzle. I also think that since I like my body that might be another reason I don't take issue with these communal showers. Please add your thoughts.