Fio is opposed to legalizing polygamy in the United States. In fact, she'd like it to be outlawed across the world.
In the first place, polygamy leads to social destabilization because it skews the ratio of available females to age-appropriate males, and the leftover males, with no hope of a future, often express themselves through violence. In the second place, polygamy turns women into baby factories--they are taught that motherhood is the only route to heaven. In the third place, age-inappropriate marriages are all too common. In the the fourth place, given human nature, not all "wives" are treated equally.
Kody Brown should be arrested and put in jail.