If we allow the banks to fail, then either savers lose their deposits or they get payed out of the general fund, i.e. increased taxes or increased government debt.
The only way to have the "banks" pay for their mistakes, rather than the customers/taxpayers, is to significantly increase the taxes/fees they pay over decades in order to replenish the funds payed out by the FDIC to recoup the losses of the customers.
But if we do that then they might just pass the added taxes onto their customers through higher fees and penalties. Or they would just go into a lower taxed business or a lower taxed country.
There really is no solution shy of declaring such reckless behavior as tantamount to treason and trying/sentencing the corporate officers accordingly.
The economic model is geared to markets these days. The commons is pushed into that, having more risk. Interest rates are pathetic, and being prudent is punished.
Might?