"The housing bubble simply could not have occurred without financially illiterate people making bets they didn't understand in the hopes of getting rich quick."

"The housing bubble simply could not have occurred without financially illiterate people making bets they didn't understand in the hopes of getting rich quick." A financially illiterate person who makes a bad bet does so with someone lending them money. In the case of the mortgage market it is a financially literate person giving them money. It's not mere convenience to place greater blame with (investment) banks.