There is an on-going debate in the community concerning singles admission policies - it has been the main subject of most letters to the American Association of Nude Recreation Bulletin for about the past year.
As you pointed out, the policy usually is to limit the number of single males that are admitted to a landed club at any one time (sometimes there may be a similar policy for females, but that’s much more rare in my experience). And you also right about the cause for the policy - single males making nuisances of themselves by trying to instigate sexual activity or attempting to pick up women. All too often, that behavior comes from men that are new to the community and haven’t learned that “nude” does not mean “promiscuous.”
“Family oriented” resorts use that term to denote a couple of things. Some resorts are more adult-oriented in that they don’t have facilities specifically designed for kids (some camps have kid’s play areas, nursery facilities, wading pools, and arts and crafts activities that are aimed at entertaining children). “Adult oriented” resorts tend to revolve more around the pool and, to be quite frank, the bar. Hedonism II is a prime example of this type of resort.
Some facilities do have reputations for also catering to those in the swinging lifestyle. The facilities are actually very, very nice and the activity tends to start later at night, in specific areas of the resorts, and it is a sort of advertised through word of mouth.
The nudist community is very, very aware that there are many people who have an erroneous conception that all nudists are having sex by the pool, swapping spouses, and living a life of debauchery. Well, some of us are , but that’s not the central philosophy of the community and sometimes we have to be very explicit about what types of activity are tolerated.
Hope that helps. If not, you might want to contact AANR - they have professional staff that can answer questions better than me.