As I said, its the environment the drive is in... enterprise. Its is being used constantly which is not a typical home use model. So sure a drive may fail more frequently in such an environment (that it is not supposed to be in first of all), but will it fail if its not being thrashed for its entire life? That is why I like the subset link I posted better than this one.
Not to mention, another site did tests with drives and the WARMER they are the less they fail (to an extent of course) so the physical environment of a data center, which is typically cooler than your home and PC case, could also play a role there.