Is there anything actually wrong with nudity? Are there actually good reasons why we can show off our hands and noses, but not our vaginas in public? Or is it crass stupidity, and will people in the future laugh at our stupidity?
I think it is a result of that fact that we have been wearing clothes for so long, actually. Over time we have gotten so used to being covered up that it is now considered rude and inappropriate not to be covered in a public place. If you want to walk around naked, that's fine with me. It's not something I'd have a problem with, though personally I wouldn't go out in public without wearing clothes.
However you look at it, making it an offence to be nude in public is pretty silly. Censoring nature is ridiculous.