Why emphasise on monogamy?

[CapnAwesome]

If we biologically were are programmed to want more partners, and even dissatisfied with one partner over time (biologically that is), why emphasise on monogamy?

Now I'm sure this is the intent for monogamy pronates but....monogamy undoubtedly has a stabilizing effect on society and monogamous (or rather serial monogamous) societies are always better for women's rights. You see that in the Muslim world and in the United States and in history. Also I believe polygamy destabizes society because what do you do with all the unmarried men? Esspecially if they are told they will go to hell or be cast out of the community if they have extra marital sex. You end up with an excess of angry horny young men, which is not a good thing for society.