That is also what women do. I read the "I can't find any good men" daily on OKC. Ranting only at men when it applies to everybody seems to be aiming at only half the target.
When speaking of various forms of non-monogamy...it ain't poly if you're just fucking around.
While polyamory, open relationships, and swinging are all distinctly different approaches to non-monogamy, they are not mutually exlusive. Folks can, and some do, engage in more than one of them at a time--and it's all good.