Would you like to hear my concocted theory? There are reasons both modern and (for Christians) historical why male over female polygamy is a bad idea. It is a form of slavery and of control not just of the woman but of many resources such as her children. It gives the man a great deal of power in society compared to the other men.
Historically there are probably other reasons. Christianity from its beginnings was about equality, and I think this factored in. Jealousy is against the Torah, particularly jealousy of someone's wife is. How can you discourage jealousy? You can insure that almost every man has a wife. Additionally it adds duties to the one man. The Torah teaches that a man must teach his children, but it seems reasonable to think the more wives he has the less time he has to do that. He must spend time with each wife, provide for each wife and her children. Clearly he can do that better with one wife than with multiple ones. In addition the stories of the patriarchs highlight all the problems they had as a result of taking on multiple wives. These stories aren't there for no reason.
Another reason why polygamy would be seen as bad historically is that Christianity disagreed with the idea of physical perfection that Greece embraced. I suspect it rejected all racist concepts, eschewing physical perfection through breeding. Where many societies held it a responsibility to breed the best (through polygamy), Christianity did not (or ideally did not). I think it got this from Judaism which held all blood to be equal, and at the time of Christianity's formation the Judeans were still being oppressed by Hellenic influences they viewed as unlawful impositions: nudity, homosexuality, physical perfection, Greek language and mythology. From time to time the Greeks thought it their duty to impose Hellenic culture upon Jews, so this probably encouraged a very strong rejection of all of Greek culture among certain Jewish groups. Possibly this rejection was one of the early influences on early Christians, although later there were things they borrowed from Greek culture, particularly its philosophical tools.
