Wealth residistubution you mean. Often there is a great disparity in motivation and income between the spouses. Divorce will redistribute wealth without regard to merit. (Especially in community property states)
Furthermore, there is a cavalcade of attorneys who will also benefit from the dissolution of the marriage.
A good article on retribution of assets as will as the effect of pre-nupituals is:
http://www.economist.com/displaystory.cfm?story_id=2709223