There is widespread agreement that the primary cause of the current crisis is the bursting of the housing bubble followed by delinquencies and defaults by homeowners on subprime mortgages. Because of historically low interest rates during the first half of the decade, the extension of credit grew dramatically. So-called "predatory lenders" devised subprime mortgages to lure those unable to qualify for a conventional mortgage into the housing market.

Predatory lenders offered prospective home buyers with low incomes or poor credit histories loans structured appealingly in the short term but whose adjustable rates caused a sharp increase in payments after a couple of years. As long as housing prices continued to rise, home buyers were told, they could seek advantageous refinancing before the higher rates took effect.

Instead of maintaining a relationship with their borrowers, lenders then sold the mortgages—which were then packaged into residential mortgage-backed securities, in which investors collect on interest rates and principal payments—and kept the loan origination fee. Thus freed of risk for writing subprime loans, predatory lenders continued to find ways to entice new home buyers into the market.

Source

That "at one time" is critical.. and paying full retail is insane.

So where's Uncle Sam for all those good citizens who need help with their mortgage payment? Where's Uncle Sam for giant money grubbers? Right in their pocket. Just say no to 'tards