Inevitably when discussing mortgages there are people who made decisions they stand by because either they worked out for them or they expect them to. And, yes, for people who got sensible ARMs at the right time and who either expected to and did sell within a short period of time or had low or no prepayment penalties so that they could refinance and did so before the market started to tank, your mortgage may have worked out perfectly for you. Yay you!
So, yes, basically people who got ARMs with sensible terms in a period when home prices were rising, not falling, you might have saved a lot of money. But lots of people didn't get loans with anything resembling sensible terms, have giant prepayment penalties, cannot afford their mortgages, and are unable to refinance because they're currently underwater. Bummer for them! That's the point.
