The major difference is that capitalism allows the individual to rise in his standard of living through his own initiative, whereas in Communist regimes, the individual is stuck with what's mandated to him by the state. So instead of moving from a three-room apartment to a nice house in a suberb because you went from working on the loading dock to a middle-management position (or better yet, you started your own business), you spend the rest of your life living with six other people in a two-room shack with bad plumbing and a leaky roof, gutting fish in a commununal factory for fifteen hours a day at the rate of five kopecks per hour. Workers of the world, despair.
I quite agree, but it's not forms of government that will keep this in check. The only way to keep mankind's fallen nature from devolving into predatory exploitation is a firm belief in the teachings of Christ---the "Golden Rule", if you will.