Luckily her at our local dances, (NH), dancers are encouraged to seek out newer dancers and folks that appear new to the dance, this fosters a real community feel. More to the subject; I was at a dance to the south of here and if I wasn't asked to dance ahead, or booked ahead myself, I would have watched from the sidelines. I think this is ingrained, and accepted practice at certain dances. I don't think there is much a caller can do to dissuade it. Dancers are going to do what they are going to do. The best a caller can do is try to set a good example, toss out the style points and, and try to present the best dance experience possible. (also push those smaller dances where booking ahead isn't so prevalent). Thanks Gale