Heritage overlooks the obvious.
The entire fiasco was the result of the Community Reinvestment Act.
And that's just starting to name all of the culprits. There also are millions of individual culprits, namely folks who bought far more house than they logically could afford - and were enabled by the brain-dead mindset that took over the political, regulatory and financial sectors.
Exactly spot on, Morgage Back Securities, and everybody knew they would crash at some point.