Well, for the record, most of the fat villains out there ARE fat because they eat too much - you often see them pigging out on huge portions of food. I understand what you mean, but fatness as a means of showing that the person is greedy is just too obvious a visual metaphor for it NOT to be everywhere. (Which is not to say it wouldn't be interesting to have a greedy villain who ate a lot and was thin as a rail due to having a good metabolism.)