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!"
Unfortunately, when one economic domino falls and sets of a chain reaction leading to a market crash, a lot of hard working and responsible people get caught up in and swept away by the ensuing tsunami.
Even if people are rational about this, the 1980s saw an increase of interest rates above and beyond 14%. If 1980s style stagflation ever hit today, I can assure you that even the "rational" home-buyers who fully understood the clauses would be forced out of their homes.
In any case, being forced out of your home, even if it is a situation you set yourself up for, is a traumatizing situation. I think we all can agree to that.