There is one article where he writes how people/hackers get rich by creating wealth [1]. This is not the case with Travis and Uber, which the article I've linked to shows.
It's also mentioned in his article on economic inequality where he asserts that people get rich because they are more productive than others [2].
[1] http://www.paulgraham.com/wealth.html
[2] http://www.paulgraham.com/ineq.html