The politicians were elected to make sure this sort of thing never happens.
They caused it, be it through deregulation, corruption or the cheap housing used to buoy the economy for Bush to say they could afford to invade Iraq, or whatever combination is the truth, they were in power and they allowed it to happen. There is no bigger lie than a politicians looking surprised.
The banks and therefore the CEOs were at fault and should pay for their wrong doings ( no mistakes when you earn that much). The govt was the ultimate error.