Capitalism has created more wealth than any other political system in history.  The US started out as a capitalistic society. It has been degraded and attacked since the beginning and now is far from capitalist. But in those first 150 years, it did more to increase the wealth of the world than the previous 2500 years.

Plus it is the only moral system of government.   Every others system violates a man's natural rights in some way or another.