eliminating the capital gains tax would cut an enormous amount of revenue. pretty sure theres been a net average 7% yearly profit in stocks in the last 100ish years if i'm not mistaken, so don't act like people who invest aren't coming out on top for doing it. those that do lose money, whether because their portfolios weren't diverse or they just got unlucky, do have some benefits given back to them depending on how hard they fall (bankruptcy, social security in retirement, etc) and thats not even considering the expense o bank bailouts
and these mega-millionares and billionaires love a turbulent market, because they have the resources and insider information to make it work for them. like how bain capital used to invest huge amounts right when a company went public, making their shares look good so other investors would jump on the bandwagon, then pull the floor out by cashing those now valuable shares and leaving the other investors and the company fucked.
your logic about being double taxed while risking not getting reimbursed for losing money in stocks holds some water for the average individual investor, but it wouldn't make sense for so many people to be making so much money without the government getting some of that revenue. think about it, people (like Romney) who every year make millions without actually working, paying smaller tax percentages than those who WORK to make 60,000$ year, is that a symptom of a healthy society?
Romney didn't break the law, but its pretty clear how the law works in his favor. what bothers so many people is that he is fighting tooth and nail to keep it that way.