Great article. Just want to point out, you kind of missed one big group that made this all possible. Government. In 1992 law was passed that made Fannie Mae and Freddie Mac have to allocate 30% of the mortgages they bought be from borrower's that institutional investor's would not buy as their standards were not prime (i.e. subprime). In 2000 that percent was raised to 50%, and a few year's later eventually to 55%.
I'm genuinely curious as to what your analysis would be of the member's of government's (congressman, presidents etc.) incentives, greed, irrational exuberance etc.