Actual capitalism, unlike what most of us live under, is basically voluntarism. In a free market you trade with others in order to mutually gain, free from forced coercion and arbitrary rules imposed by power hungry rulers and their cronies.
Socialism has never worked, never will work, and always creates poverty and death. It goes against the very nature of how we function as human beings. It might sound good to some in theory, since it appeals to our desire for "fairness", but what it really creates is more inequality and unfairness.
"From each according to his ability, to each according to his needs" might work within a very small group where you know each other well and where social dynamics enforces some sort of fairness and punishes bad behavior. But it's a terrible principle to be organizing a society around, especially when you aim to enforce that principle.
I always find it funny how many leftist people like to show off their so called virtue by saying that the government needs to spend more money on this and more money on that, while at the same time never wanting to do the actual work themselves. It's always easy to be generous with other people's money.
"I have never understood why it is greed to want to keep the money you have earned, but not greed to want to take somebody else's money." - Thomas Sowell
