Also, consider that ability is distributed more or less on a bell curve. Effort... I don't know, but you can't work that much more than the average for that long, so bell-curveish, again. However, in modern society, rewards can be way, way outside the bell curve. Not that that's a bad thing, or illogical - a new invention that makes millions of people's lives better is worth a lot of money and should be rewarded - however, maybe it's one of the reasons that people are a bit suspicious of extreme wealth.