Well lets look at it this way. Capitalism allows people to own private property, have the right to gain wealth and compete in the market. This promotes a growing economy where competing industries produce higher-quality products. Capitalism also allows individuals to earn money based on the importance of their role in society. If doctors didn't earn more than carpenters, no one would become a doctor and we'd have a shortage. This system encourages people to contribute to the economy, thereby gaining wealth for themselves and promoting wealth for others. Capitalism is not without it's flaws, and there are many different forms of it.
hope this helps