Because they were told over and over again that buying a house was a good investment, and that the value was going to increase so much they could sell it and make money later.

Why do you hold the people who took the loans responsible but not the people who have them? How can they not have at least as much responsibility? Can't you say "just because you can doesn't mean you should" to people pushing predatory loans?

There are many, many people who deserve some blame for the housing crisis. Certainly, the people who took out loans they couldn't afford, but also:

- the loan underwriters who assured them they could afford the loans, because they had no risk, because they could turn around and sell the loans to:

- the banks who bought up the loans and repackaged them into mortgage-backed securities, which they could sell easily, because they were highly rated by:

- the credit rating agencies who gave those securities AAA ratings, which they did by completely ignoring systemic risk

- And we haven't even gotten to credit default swaps

In short: yes, there was a lack of personal responsibility on the part of buyers, but they were heavily encouraged to believe they could afford these houses, because the market conditions created an enormous demand for new mortgages, by convincing itself it could make money off of them with zero risk.

The banks also turned around, repackaged those same predatory loans, and marked tranches of them as AAA-investment quality. Where was the responsibility in that activity?

"Just because you can doesn't mean you should"

Indeed.