Well, then my competitors in the market are probably disappointed when their investment doesn't meet their expected rate of return 50% of the time. As an investor, my portfolio crushes the S&P average return, but I still realize that each individual investment is uncertain. I would say I'm "successful" about 2/3rds of the time.
I don't really care that dividends and capital gains are taxed twice. Typically, the people earning dividends and capital gains contributed nothing (or I will concede, very little) to the actual profit. In my investment account, I have done nothing to help Baidu succeed. And yet I've taken $1 and turned it into $3. I should be taxed out my ass on those $2 profit. I didn't earn it. It should be just like gambling taxes. That's all I'm doing. Playing a gambling game that isn't tilted in the house's favor. That's what "investments" are.