I blame the people who could not understand they could not afford their home loan. If you do not understand the loan you shouldn't sign the papers. I know a lot of people fell on hard times and lost homes, but most took loans they never could afford. When I was house shopping I was approved for much more than I could afford, I bought in the range I knew I could afford.
Local story, a waitress buys a home for 750k for her and her 3 kids. Her business laid her off, she said her mortgage should be reduced to show the new home value and let the rest go away. More investigating showed she never could afford it and never made a payment. Liar loans got us into this mess, the banks and the people are to blame.
Someday I hope this country returns to a state of personal responsiblity. No one is to blame except youself when you take a loan you cannot afford, or when you refinance to take a loan you cannot afford.