We could also list neo-Nazis, hate groups, etc. It is difficult to be selective without offending those not selected. At one time we allowed pagan sites for the reasons you state. There are some sites that we would like to be activists in working toward their removal from the 'net, freedom of speech notwithstanding. I personally consider freedom of speech to be of extreme importance, but not of highest importance among our desirable freedoms.
Pornography is one such category.
There's no worthwhile place for it for anybody in my opinion. It is purely evil and should be eradicated. We'll keep striving to accomplish that and seek advice from others like yourself. However, nudism has, to the best of my outsider's knowledge, no connection with pornography or indeed any sexually-explicit themes let alone liquor or tobacco. Most nudists seem to practice in family groups and those of my acquaintance do not have abused or in any other way unusual children.