First, his jab at entrepreneurs who "extract surplus value" is an appeal to the core tenant of Marxism: that all profit is an exploitation and an unfair "extraction of value" from labor. I don't want to have a knee-jerk reaction to his argument just because of that, but it doesn't set a good tone for me.
Second, part of the problem I have with the tax increase is this: who knows what all that money will be used for? It could be used for taking care of the great unwashed masses (disdainful much?), or it could just as easily be used to invade more foreign countries in the name of "freedom", prop up outdated and failing industries, or bail out gamblers on Wall Street. The government of the last twenty years seems to have been shockingly bad at allocating the ridiculous amounts of money they collect from us; why should we give them more?