I agree. Some say "no one saw it coming"...I think there were currents at work during this tragedy.
I was a bank examiner from 2000 - 2005. We all saw the loans that were being originated probably as early as 2003 (and not all banks were doing this. Mortgage brokers were more likely to originate these types of loans generally). What we didn't understand from a field level view is what this meant at a macro level. As long as property values were rising, nobody could lose.