Posting on "nudist" sites to advocate nudism is preaching to a very limited choir. We have maybe a couple hundred regular readers here? Other nudist sites have fewer or a few more. We only reach people who have decided to become nudists and looked for a nudist site. It doesn't reach the millions who aren't nudist.
Some of the millions on other sites may learn more about nudism or may become used to seeing nude humans as a normal choice. I like a Facebook site called Nudism is the Way Forward, but again only those who look for nudity and "Like" NWF will see it. Of course, also, Facebook censors photos so it still has a meta message that whole bodies are "obscene" and can't be seen.
Similar Worlds doesn't have as many readers as Facebook yet, but its growing. Most of them are not nudists but now they interact with and see nudism every day. Some of them are nudists. Today there was a member of International Young Naturists who posted her story and IYN emblems a couple of times. Rather than preaching to the choir its an outreach to the textile world.
Yes, SW is "rough and tumble" with a very wide variety of personal fetishes, activities, and life stories that people want to share. Politics, religion, sex, crime, bodies, relationships, every topic you could want. And, it has a continuously present advocacy of public nudity among people who think of themselves normal. It is NOT a "nudist site" with a few regular men and only occasionally a woman having a polite conversation. It is a whole population site with lots of every kind of person.
I think its a WIN for nudists to post casual nudity as a regular choice among the whole population. Your opinion may differ.