Many people visit DCHS and not all of them are well behaved. Illegal camping, illegal fires, vandalism, and littering are all too common.
I agree that the guy who followed you around (7 years ago) behaved inappropriately.
Your wrote, "Somehow, I am pretty sure the people who drafted that suggested rule of etiquette see things just as I do." I doubt it. In your previous message you wrote "I just meant time alone, romantic time, maybe kissing and caressing, enjoying the silence or soft whisperings between lovers." The Naturist Society promotes family-friendly nude recreation and goes out of its way to repeat that naturism is not a euphemism for sexual behavior. Get frisky with your lover in your own hot tub, but not in a public venue please.
http://www.naturistsociety.com/resources/NewBeachEtiquette.html
http://www.naturistsociety.com/TNS%20Web%20Site%20May%202010/FAQs%20Page/template2008NEWFAQPage.htm