It's a cry of relief. You'll run into some of the most interesting, friendly, people you'll ever meet. Because social nudity isn't a mainstream activity, being open-minded and having the guts to thumb one's nose at cultural stupidity is a prerequisite in this group. That alone would insure an interesting mix. Moreover, much of the baggage that our culture entangles with clothing seems to come off with the clothes.
People tend to be more open and themselves when they're nude.
Maybe it's because it is such a special thing. Maybe it wouldn't be so special if the world wasn't so screwed up. You'll meet men and women of all ages from children to grandparents. You won't know or care if you're talking with a janitor or a doctor. You'll meet interesting people who you might otherwise never meet.