Genuine nudism/naturism isn't anything to do with sex, it's about being free to not wear clothes and see the human form instead of hiding it. I have a few nudist friends and contrary to popular belief they are not jumping on each other.
For me clothes are about warmth and protection from the elements.
I have no desire to spend my time, paid or otherwise meeting some random bloke in the middle of nowhere, for him or both of us to them walk around naked in public.