Polygamy is STUPID!
Depends what your goal is. If you'd like to ensure a large supply of disaffected young men who can be used as soldiers in wars of conquest, polygamy seems an ideal feature for social organization. A certain evil false prophet, depicted here with a bomb for a turban--
`O(:-{>
--understood this centuries ago.
BTW: emoticons are held to violate the Islamic prohibition on images, so I guess I've got a fatwa against me now.