First of all the Mormons practice polyGYNY not polyamory or even properly polygamy. The religious practice of taking more than one wife while denying the women the right to the same practice is NOT polyamory at all. Polyamory isn't a religious practice though many of it's adherents are, indeed, highly religious. The poly lifestyle allows both men AND women the opportunity to love as many people as they are lucky enough to find that special connection with. This is not the case with polyandry or polygyny.
I believe that when the issue of polygyny was first brought up during the early years of the Mormon church there was a need for women to have the protection and support of a husband and this lifestyle filled that need. I do not believe in the 'celestial' marriage and becomming 'Gods' after death as this is NOT what Christ taught his followers. The thing is most Mormons don't espouse or agree with the philosophy of Polygyny. This isn't a small 'fringy' religion but a very large and thriving one!
I don't think any rational person would ever agree with marrying younger and younger girls while driving away young men, which has been alledged to happen in these compounds. I do agree, however, that if a young girl should believe in and wish to live in a plural marriage then it should be her choice...after she has reached the age where she can be reasonably able to make that choice. That seems to be the same age as thier non-plural marriage minded peers, around 18-25. I have been on a lovely compound and been very intimate with plural families and while I don't agree with their philosophies I also don't agree that their children are 'brainwashed' anymore than any other fundamentalist or non-religious family's children. Most of the women I met were rational, happy and content with their lives so I know it CAN work in a rational society...if any religious society can be called rational.
I abhor and decry the subjugation and degredation of women where ever it is taking place, I also abhor telling anyone that their CHOSEN lifestyle is inherently wrong so long as it isn't causing imminent harm to it's adherents. Yes molestation and forced marriage and subsequent rape of a "bride" is wrong, but so is caning woman publically for being in a bedroom with a man who is not her husband just because her neighbors "THINK" something bad is going on...
I do not, however, think that plural marriage is degrading or subjugation when it is chosen by it's participants. It's right for those it works for and wrong for those forced into it...sort of like my views on making monogamy the only right and true way.