I'd like to consider a related question: why did our society "choose" monogamy as a social norm? One major clue is the high correlation between monogamy and economic development--virtually all modern industrialized societies have adopted monogamy as a social norm, whereas most societies throughout history have practiced polygyny. But what direction does the causal relationship run? (*)

Does it make sense to start tearing down this norm before we get that question sorted out? Several commenters have said that they're not for or against polyamory, but they are for being aware of and considering the possibility of polyamory. But one way to enforce a social norm is to teach people to think in such a way that they do not even consider the possibility of violating it.

* See http://emlab.berkeley.edu/users/webfac/bardhan/e271_f05/tertilt.pdf for one attempt to answer the question.