It's a fair question: "compassion" is a vice, when practiced by government. But isn't it still a virtue when practiced by individuals?
The Objectivist position is that moral pressure, and guilt, are just as coercive, and just as wrong, as government coercion.
So, the liberal position is this: "We" should take money from B to give it to C. B is rich, and C is poor. But "We" does not include rich liberals, like Al Franken, who think that only saps pay taxes.
It's not charity if it's done at gun point. Is it charity if it is done out of fear of shunning?