From the article: "While it's true that most Mormons have polygamists only two or three generations back in our family tree, the Mormon Church today does not endorse the practice of polygamy."
That's because the church is hypocritical. One of my biggest objections to the LDS church is that it DID stop officially practicing polygamy. If polygamy is part of your doctrine, then you should bloody well practice it, and to hell with everybody else. (Of course, their brand of polygamy was completely sexist and extremely offensive, but a lot of America was like that back in the nineteenth century.)
However, I don't single out the Mormons. I have objections to a wide variety of other religions, too.