It was interesting to watch the conclusion of HBO series "Big Love," as the writers decided to follow a surprisingly libertarian (instead of moralist) path.
On one hand, they chose to make it very clear that the three wives of Bill Henrickson were in the relationship due to their own will and free choice. This statement was made very clear during the last few episodes, when every party in the relationship had the opportunity to leave the multiple marriage, very good reasons to do it, and yet decided to recommit to it because they conscientiously believed that they were better off in it. Even the "cult" motif was discarded once Margene Heffman chose to abandon the "real cult" she got involved with.
Tragedy and redemption, even if overused as a narrative solution, always makes for good storytelling as long as the outcome remains hard to predict, as it was the case with their wrap up choice. What I found interesting however is that the tragedy itself is in line with some of the theories that try to explain why societies have traditionally decided to ban plural marriages, in this case, competition exclusion and the maintenance of social peace. The same argument may also explain why serial marriage arrangements haven't faced similar oposition in open societies.