Regardless of where the earnings of the wealthy come from (income or capital gains), it does not change the fact that they pay the majority of the taxes used to run government. The cap gains rate may be lower than high wage income rates, but it still produces massive tax revenues. Sorry, you can't wiggle your way out of this one. Hell, many countries have NO capital gains tax. We have the most progressive tax structure in the world, no matter how you cut it. Fact.
I just wanna know why passive income should be taxed less than earned income.
Several reasons. First, experience suggests that a low rate of tax on capital gains increases capital investment and new business formation. This is why many countries have NO tax on capital gains.
The justification for a lower tax rate on capital gains relative to ordinary income is threefold: it is not indexed for inflation, it is a double tax, and it encourages present consumption over future consumption.
Inflation: Cap gains is not adjusted for inflation, so any appreciation of assets is taxed at the nominal instead of the real value. This means investors must pay tax not only on the real return but also on the inflation created by the Federal Reserve.
Double taxation: The capital gains tax is part of a long line of federal taxation of the same dollar of income. Wages are first taxed by payroll and personal income taxes, then again by the corporate income tax if one chooses to invest in corporate equities, and then again when those investments pay off in the form of dividends and capital gains. This puts corporations at a disadvantage relative to pass through business entities, whose owners pay personal income tax on distributed profits, instead of taxes on corporate income, capital gains, and dividends.
Consumption: A capital gains tax, like nearly all of the federal tax code, is a tax on future consumption. Future personal consumption, in the form of savings, is taxed, while present consumption is not. By favoring present over future consumption, savings are discouraged, which decreases future available capital and lowers long term growth.