The economics behind it make sense as well. A used computer will retail anywhere from $100 to $500. The information in it, if not wiped correctly, will average many times more even if you factor in the purchase of data recovery software. Criminals have different ways of capitalizing on personal data, ranging from selling the information outright to engaging in something with better returns.
Is there a better way to protect oneself? Whole disk encryption is a way to ensure that such problems do not occur: One can just reformat the encrypted drive itself to install a new OS; the original data remains encrypted, so there's no way to extract the data. Plus, the added benefit is that the data is protected in the event that a computer gets lost or stolen. However, commonsense dictates that encryption is something ongoing concerns sign up for, not businesses about to go bankrupt. My guess is that sooner or later we'll find instances of data breaches originating from equipment being traced back to bankrupt mortgage dealers.
