Atrios points out what should be (but isn't) obvious, and should be clear in the reporting (but isn't):
It is not and never was about the borrowers. It's solely about predatory mortgages. Obviously, the borrowers had no significant problems with initial loan terms or even slight increases in payments. But the lenders had to big pigs. For what legitimate reason other than simple greed? Had they stuck with flat rates or more horizontal increases, they'd have been covered by a relatively strong market with continued increased valuations. That is, growth. Instead, they went for a bubble. And Big Banking exacerbated matters with their nutso repackagings of the debt: repackage crap where no one knows what's in the packages, what they're worth, and, for that matter, who are the actual, underlying debtors.