The US tax code is regressive as far as wages and earned income go. Investors are treated very well; even high earned income folks are relived of much of the payroll tax as East points out.
I'm generally supportive of capital gains treatment, especially when it encourages investment in new ventures. But when it gets gamed so that what is really earned income is taxed in the same way as those who put up real dough (e.g., managing a VC fund in which one has no real capital at risk), it undermines the fairness in our system.
I remember from Econ 1 and later from tax courses, that by and large Americans pay their taxes without cheating. Unlike most countries (think Italy and Greece for example). The reason given was that most Americans think the tax system is basically fair. If we lose that agreement, we are headed for more trouble.