You ran the numbers wrong. If 250.000 characters looted 566.000 gold, then there is no way it is less than 2 gold each. To be exact, the average gold looted for all characters created is 2g, 26s and 40c. If we assume that all the gold is looted by characters above level 10, then the average is 2g, 51s and 55c. And as most gold comes from quest rewards and vendoring items, it is plausible.