Indeed, it is a problem brought
in France by noneuropean
foreigners.
I don't even want to imagine how it would be like to live with over 40 brothers and dozens of 'stepmothers'. The person that said it hurts children has a point. What kind of atmosphere does one experience if for example some of the women in the household start fighting for money, or swear at each other, or nearly kill each other over some jealousy attack...
One wife alone can be trouble in the household concerning domestic fights. Multiply that by 11 and see what one gets.
Concerning polygamy, on a general note, I think that even if we are poligamous by nature, we, as Europeans, are generally monogamous culturally speaking. That's another thing which differentiates us from other cultures. The Talmud for example allows polygamy but the number of wives is limited, just like in the Koran. (no?)
Though there are also controversial opinions regarding this subject, example:
http://pyramidprophecy.net/polygamy.htm