I think that show is simply a sign of the times we're living in. God intended for one man to have one woman. That's it!
This is as naive as it is ethnocentric. There's a big world out there. Just because your beliefs don't match others does not mean that yours are universal and everyone should obey them. Polygamy has been around for a loooong time. Even in your holy texts.
It still doesn't make it right.
Many people believe that what is right isn't always universal. Yes, murder is bad, but polygamy? It just squicks me out, but in polyamorous relationships, they are fine tuned and each person delivers something unique to the relationship, and it seems to work for them. Personally I believe that relationships ideally work best between two committed individuals, but that isn't the universal viewpoint, just the popular one. Many committed two-person relationships are also "open" relationships, where the people have fine tuned the option of being with someone who isn't one of the two original partners in the relationship. It isn't something that works for me, and although I think what they are doing is wrong for me, I won't tell them that they are living their lives wrong. The main issue I see with polygamy, though, is that it isn't an equal partnership in cases like the tv show that started this thread. Any relationship that isn't an equal partnership is definitely wrong...period.