Albacore hit it dead on. It's the prudish mindset of most Americans to think this way. Go to France, Italy, Greece, Spain, etc... Nudism is normal. Kids and adults attend the same pools and beaches and without (gasp) clothing. Or it's clothing optional and some are only partially clothed.
Yet in most American cultures, the body has to be kept like Muslim woman, all covered up. We have to set aside small patches of beach or special living facilities to allow those that want to go around with no clothes to do so. I remember as a kid going to beach every day. We never wore swim trunks or bathing suits. But much past 5 or 6 years of age you had to due to the suppressed perverts that were starting to come out of the closet.
Ahh for the days of the Hippies having free love and sex in the parks. I still have those first visions burned into my brain. And they were from 50 years ago.