This is a proposal that would do a lot for the economy. How many people rode down big winners from the bubble market because we didn't want to pay taxes on them. I know I did. But for cap gains taxes, those profits would have been realized, taxes paid on it and it could have been reinvested or spent, instead of letting a bunch of wall street crooks keep it.
Another thing that gets lost in the argument is the idea of who benefits. Typically, these tax cuts(ok, ALL tax cuts) are opposed because they "only benefit the rich." Particularly with the dividend cut but also with cap gains, the idea is to get more people involved in owning stocks so that more people benefit. I'm sure the same argument was made when they proposed letting people deduct mortgage interest, "It's not fair, only the rich own houses."