Musk is not an exception.  History is absolutely filled with entrepreneurs in the same vein.  Disney, Rockefeller, Ford, Jobs, Branson, just to name a few.<p>And those may be some of the more standout examples, but there are hundreds of thousands of entrepreneurs who have made similar reinvestments or expansions to some smaller effect.<p>The carpenter who invests his post-tax capital in buying better tools or increasing his skill is producing a net-positive effect for society by improving the quality of carpentry available to people in his area.<p>Our economy is in large part, the net effect of the sum of all those micro-improvements.