The culprit behind the global financial crisis is excess consumption, funded by debt.
Before we condemn the banks we need to consider what was going on in 2009 re: TARP and political pressure to force banks to make liar loans available years before the crisis.
Although I do not suggest the banks should get out of jail free card I do think there were forces that put them (and the country) in a vulnerable spot outside of their control. If you want to find out why the creek is muddy...go upstream. A huge portion of the mud came from Washington DC in the 90's.