Polygamy is not adultery.
That’s not what the article is claiming.
That could be debated. But it is clear from the bible that polygamy was not God's design for marriage from the beginning.
Gen 2:24: A man shall leave his father and mother and cleave to his wife (not wives) and the two (not three or four or more) shall become one flesh.
Arguable, but the point isn't whether polygamy per se is adultery. The point is that a woman who commited adultery could face criminal penalties while a man who committed adultery could not, which was fundamentally unjust and was based on a culture that condoned polygamy (but not, of course, polyandry).
It is possible, as a matter of theory, that there could be a society that both condones polygamy and respects the equality of women, but I cannot think of one that has ever existed. Every polygamous society with which I am familiar -- including polygamous subcultures in countries like the US where it is not widely acceptable -- abuses women, including "women" whom most of us would consider girls.
I live here in Kingman, Mohave County, AZ. So far two members of the Warren Jeffs Cult have been tried here. The sentances they received are laughable. The fix is definatly in. When Nevada is done with Jeffs and he is on trial here he will get a walk for sure.