Here's how it really goes:
People want to do things that they want to do, and get things that they want. The idea, for someone who can think beyond the interests and needs of the moment, is a means to optimize one's ability to accomplish these goals. In capitalism, this is done through exploitation. In socialism, this is done through theft.
The capitalist looks around for a need that is not being met, and labor cheap enough to supply that need. He puts together a system by which these needs can be met, with as little effort on his part as is possible. Initially, a great deal of creativity and effort is necessary to get the enterpise started but, with luck, and a favorable social system, he can achieve his goals. This inspires other to do the same, and so on.
In time, there are lots of these enterprises. The pickings on new ideas becomes scarce. Socialism is an answer to this; it strives to justify the stealing of already functional enterprises, ostentatiously in the name of the community. Inevitably, it is found that the dinosaur business cannot survive without the walnut-brain capitalist entrepreneur. This is why the social democracy of places like Germany are so successful - they marry exploitation (welcomed by workers) to a managed theft (necessary to avoid the explosive effects of "workman as cog" so popular during the totalitarian era). But socialism, in its raw state, is self-destructive, leading inevitably to places like Russia, North Korea, Cuba, Vietnam, etc.
As capitalist societies become more developed, the earning power of the capitalist workforce must naturally rise, if for no other reason than to provide a market for all that productivity (a resolution to Marx's "shrinking markets"; even Henry Ford picked up on this). Since workers exploited by capitalists live significantly better than (most) people in socialist systems, the former is a far more popular model. Likewise, since capitalism is not locked into observing the teachings of a dated itinerant, they can freely absorb those ideas of the Left, from time to time, that enhance the stability and productivity of an otherwise laissez-faire economy - Keynesian manipulations, for example, or social programs that benefit the elderly and crippled. Alan Greenspan is in charge of the former, and the U.S. government has become an expert at the latter (as judged by all that desperate immigration to this "accursed haven for capitalist exploitation").
O.K., now? Can we move beyond Marxism at this point, for Pete's sake?
Dr. "Nicodemus" Cruel