Those who think that responsibility for the financial crisis lies mainly at the door of governments and central banks might like to consider the following.  The policy of easy money and cheap credit, designed at the behest of politicians to smooth the down side of the business cycle, had one unexpected result.  by depressing interest rates it was made difficult for fund managers to gain decent returns on relatively low-risk investments such as bonds.

In search of decent returns in this low interest rate climate, they were forced to climb the risk ladder, investing in things that carried higher risk than they would otherwise have taken.  So while it is true that some investment groups were undertaking riskier investments, it was not because they had suddenly become greedy and reckless, but because government policies had denied them adequate returns on the safer things they would normally have gone in for.