As has been mentioned here before, the premise of this debate (as to whether taxation and wealth redistribution are equivalent to charity) is just not very interesting. A much better question to ask is whether taxation and wealth redistribution is a net benefit or net loss for society, relative to what that money might have otherwise accomplished (charity, spending, or whatever else). When you put the question that way, you're now just arguing whether or not you support Libertarianism.

I think it's fair to say that market forces, alone, are insufficient to arrive at a modern, civil society. You need redistribution of wealth to allow for everything from the military to road building. Along the same lines, it might be perfectly rational for society to create some kind of "safety net" (a.k.a., "welfare") to provide for a minimal existence, no matter what. If you lack that, then you set the stage for people with truly nothing to lose, and that, in turn, is one of the prime ingredients in a variety of societally undesirable behaviors.