So you want to blame people who probably didn't fully understand what they were signing up for (not least because they probably weren't responsibly disclosed to) for having been fleeced by crooks peddling predatory loans?

I'd bet real money that almost every applicant for one of these mortgages was reassured up, down, left, and right by the broker (whose interests were most definitely not aligned with the applicant's) that everything will be fine. "When the variable rate kicks in, you can just refinance. Rates will be lower than ever!"