Good point Vegas most of the average investors stocks are purchased after already passing through thier income tax bracket.
Except that... that is not how it is at all. The majority of wealth in this country is inherited. You are painting a picture of some hard working dude who makes it big after paying taxes for many years, and so are saying a break for him afterwards when he simply invests his millions is OK. While that scenario happens, it is just a fraction of how the money circulates. My close friend paid roughly 14% last year overall. He doesn't know what work is. He was given a hundred million dollars by his grandfather. The only thing he does for work is press the stocks button on his iphone to see how his $100K a share berkshire hathaway stock is doing. When you talk about the ultra rich, this is pretty much the scenario a lot of the time.
Furthermore, even if it wasn't, tell me why you should pay less because you are really rich and earn most of your money from your money. Why should you suddenly get special treatment? Why should you pay a smaller percentage than the hard working stiff who works 60 hours a week? Good for you if you earn more and it is through investments, I am not saying you should be punished, but why not pay the same rate as everyone else?