IMO, you get what you get. Happy Bay (and other less populated beaches where nudity is tolerated) has local bushwackers and I've seen a tourist engaging in similar activities there.
I've seen locals and tourists acting inappropriately at Orient Beach. The last time I was there (OB), I confronted a tourist taking photographs.
I don't let these isolated bozos ruin my trip. Happy Bay has always been and will continue to be a part of our SXM experience.