Really? Why do you think that?
I was browsing the discussion on the recent Showtime TV Poly show... and many of the posters here seemed disappointed that the show had many fairly graphic sex scenes, and a lot of the conversations were about sex... and many of the posters seemed to view that as not representative of the community in general... and that gratuitous sex displays and episode topics where only to enhance TV ratings. Personally I thought the show was very well done all things considered. I hope they extend to a second season.
Other threads I have read seem to avoid direct sexual focus.. and certainly swinging is like black sheep cousin who won't behave properly. Many of the regular posters here come across as very judgmental if Poly is expressed in a way that is different from their own belief system on the subject at hand.
Certainly my wife and I are totally capable of both swinging and poly... we see them as under the same umbrella in many ways, but different it some ways such as commitment level, time frame, or simply blending lives in a more complete or integrated manner.
We have swinger friends who think Poly folk are literally out of their minds.. and Poly friends who view swingers as superficial shallow heartless sex addicts. Our feeling is that there is a lot of cross pollination going on.