[–] OdinsMessenger ago
Really, they aren't as common here as fph likes to make them out to be. Sure, plenty fats use them, but it really depends on time and place. It isn't like every time you leave the house you're going to see one.
But other than that, it's because the fat issue in Oz is new enough that the fats haven't completely destroyed their bodies. Give it another 5-10 years and they'll be just as common.