Look, I'm in my early 60's, and I'll back you up. When I was 10, our class went to the YMCA every other week to use their pool. Some had suits and some didn't. Note the 'M' in YMCA. There were no women or girls in attendance, and I have no doubt that if any showed up, we would all be in suits.
The story is not that some people enjoy swimming in the buff. The story is that this jerk doesn't have the common sense to cover up when non relative women are there for their jobs.