Modern market ideology does tend to assume people controlling the government and various agencies (for instance, Bernake) are motivated by selfishness.
It also assumes that the home-borrowers, politicians, realtors and bankers who created the housing bubble were motivated by selfishness, as were the hedge fund managers and bankers who helped pop the bubble.
I don't think that this is a conspiracy theory. Just observation (fairly obvious, although I am not sure if right in that case) that selfishness can sometimes lead to actions that harm economy and the people.
It also assumes that the home-borrowers, politicians, realtors and bankers who created the housing bubble were motivated by selfishness, as were the hedge fund managers and bankers who helped pop the bubble.