You overlook a few important points. First off, Investment bankers, the masters of the universe, got enormously richer even as they rode their corporate steeds into the dirt. If you think they were personally invested in the bunk they were peddling, you're out of your mind. They're diversified worldwide, financially unassailable.
You ignore the effects of top tier windfall "tax relief" entirely. That led to a lot of hot money & willingness to speculate. The wealthy put thier money in hedge funds gambling on derivatives & upper middle class people started flipping houses as never before, speculating on Florida condos & Arizona winter homes, all of it based on the theory of the greater fool.
Finally, you discount the importance of leadership entirely, and that's a big factor. GWB touted the ownership society from the bully pulpit, and every right wing pundit & prognosticator joined the chorus. The Bush Admin facilitated Wall St in ways beyond that- with ridiculously lax enforcement of existing regs, stymied state regulators, relaxed net capital rules even as they demanded that the GSE's take on more "affordable" loans, even buying Wall St's MBS.
We didn't just fall into this trap- we were led into it, the same way a Judas goat leads sheep to slaughter.