Wut. I've dabbled in the kink scene in the past (which has lots of crossover with the swingers scene), and there are plenty of older folks that swing.
The responses to this thread are kind of strange. I tend to think that poly folks are overly interested in sexual gratification, but that's their choice to make. I'll agree with the TS that many of the folks in the scene are much more mature, open and honest about relationships/stds/kinks/interests, and intellectually curious than the general population. There's also a huge part of the scene that are the most socially awkward/weird people you've ever met, multiplied by a 1000. Its usually one or the other.