I wonder if one reason it is so difficult to make polyamory work is that we are so ill-prepared to try it. What I mean is that all of our cultural training is for monogamy. Our institutions support monogamy rather than nonmonogamy, so it isn't any wonder that monogamy works for more people. I wonder how many people polyamory or other nonmonogamous options would work for if those were also supported culturally and by our institutions.
(I'm headed over to the thread Tom_Paine just started to take up the question of replacing one limiting ideal with another.)
...because public space really matters!
Elizabeth