It was the massively popular government policies of aggressively encouraging lending to people flatly incapable of replaying the loans. This was the problem. Of course they're doing it again. Promising people they can have a house that they actually can't afford is a huge vote winner. Rigging the market to make sure property prices go up, making home owners feel wealthier is a huge vote winner. Blaming nasty bankers for making it all go wrong also neatly avoids having to take any of the blame.

Take the Greek and Spanish economic problems. Spain was in massive property bubble mode for the entire 2000s. The Greek government was willfully deceiving both it's people and the EU about it's finances. We're expected to believe that these issues would all have worked out fine, and these economies would have naturally stabilized all by themselves if it weren't for the wicked machinations of the US treasury? Really?

Of course Lehmans and the other banks badly underestimated their exposure, but the regulators that are cracking down on the banking industry now and ticking them off for being so greedy, were themselves willfully ignoring all the signs of danger before the crash because it was politically expedient to do so. It was politically expedient because that's what the voting public wanted to believe. Nobody came out of the crash smelling of roses.