The right to choose what one does with one's own life, and then to earn success because of one's choice, is essential to happiness. Nothing given to us, no matter how much we want it, can make us as happy as that which we earn.
My way of comparing free enterprise or capitalism with socialism is that in socialism, one is primarily concerned with insisting that others make you happy; capitalism is based on your desire to find ways to make others happy. Socialism is directed inward at "me me me!" Capitalism is directed outward toward "how can I help you?"