If your only criterion for blame is the beneficiary then I can see how you would conclude the bankers are proportionally immensely more responsible for the problems than the politicians.  But some of these big bankers and the politicians were (are) in each others' pockets - at least if looking back at how Gordon Brown as Chancellor of the Exchequer (prior to becoming Prime Minister) in the UK behaved is anything to go by.  These politicians want power; and to do that their parties need funders.  From what I understand it's even worse in the US.  But that you seem so incredulous that policies brought in for popular political gain, followed by more to try and solve the unforeseen problems of the first, followed by more to try and solve those etc. would leave us in such a precarious position is surprising to me.  In the UK they're doing it again.  Bringing in policies to guarantee first time buyers mortgages to encourage banks to lend, thus starting the balmy process once again.

I do believe it is a myth that entirely free markets would provide the mechanism to banish boom and bust to the history books but without all the laws and protectionism both preventing newcomers from entering the market and from irresponsible establishments reaping the consequences of their ridiculous risks - all the fault of politicians - and those who vote them into power - I can not believe we would not be much better off.