At the end of the day, many people are *at fault* for facilitating the speculation and frenzy surrounding R/E in many areas. But, also at the end of the day, it is up to the prospective homeowner/investor to know how to value the investment. THAT is, truly, the fundamental problem. The facilitators at banks, mortgage lending arms, credit rating agencies, investment banks, and stupid investors buying crap paper... they aren't the problem, just the lubricant for a market out of control.
People don't know how to value assets. They didn't in 1998-2000, and they wanted to blame shady investment bankers/analysts on their 2002 misfortune. Same here. Except, through leverage, many zero-net-worth people are now in the hole by 5 or 6 figures -- something not possible in/after the 1990s stock market.
THAT is also the reason this will take years to sort out. Virtually everyone in these hot real estate areas, that purchased since, say, 2004 overpaid.