I am of the conviction that polyamory is the future of human culture. We won't get there for a long while, certainly not before we get much closer to an egalitarian society in which neither wealth nor gender determines any person's worth.
Monogamy--especially in an era of small nuclear families isolated from extended kin and neighbors--is just inherently unstable. It puts too much pressure on marital partners to fulfill too many roles in one another's lives, and the whole system can be stressed to the breaking point by any change affecting any member.
Add to that the way our lives are (or were) getting longer, and the pace of change around us, and our increased exposure to a world of cultures and ideas, and I cannot see how lifelong monogamy is a tenable model for primary relationships.
Finally, as a former psychologist, I am painfully aware of how many people are traumatized by the pathology of family members or warped by (constitutionally protected) malignant belief systems within the home.
I'll be saving your article for future reference, as I plan to write about this future vision sometime in the next few years. I am tremendously impressed at how cogently you have sorted out and explained the issues.