Plenty of "normal" people outside of HN visit saunas, nudist parks, and nude beaches. It's perfectly alright not to be comfortable with doing so yourself, but other people feel differently.

Then again, there are societies that will shame (and do worse things to) women for showing their hair or skin to strangers.

If you're (un)lucky, your innocent holiday pictures may make the front page of Wikifeet, but that doesn't mean you're a creep for posting your holiday pictures online. There's a spectrum here and claiming to know the absolute truth and branding everyone else as perverts is silly.

Personally, I find the puritan idea that any nudity is sexual to be quite childish and immature.