Why doesn't 'greed is good' work? Because rather than work harder, a certain portion of the population, not necessarily the most productive and intelligent, will immediately seek rents and extraordinary income obtained by unnatural advantages, by gaming the system, by cheating and coercion, by the subversion of the rule of law, which will sap the vitality of the greater portion of the population which does in fact work harder, until they can no longer sustain themselves. And then the greedy seek to expand their venality, and colonies and then empires are born.
A most excellent post.
1'Modern Economic Myths and the Failure of Financial Engineering' - Jesse's Cafe Americain