Incentivize him to make money for himself? I'd like a discount from society for doing that myself. How much does Romney actually contribute to society as a whole by making so much money for himself? Why does he deserve a discount?
You are talking as if capital gains don't increase efficiency the company, help produce more goods and services for the people or create/eliminate useless jobs via automation. He only gets to keep money for the value he creates for the society. Society gets to keep the value.
Now he might be corrupt or using loopholes, but that's smth we need to fix.