Olympic champions are not greedy, but make a lot. So not always true. Actually, in France , one philosopher - Bernard-Henry Levy- is actually a billionnaire. Exceptions that confirm the rules?
Olympic champions are 6 sigma individuals by design. I also know of one economist who is a good trader Trading is greed. If you are not very very greedy you never make it.
Aristotle Politics 1259: Thales, so the story goes, because of his poverty was taunted with the uselessness of philosophy; but from his knowledge of astronomy he had observed while it was still winter that there was going to be a large crop of olives, so he raised a small sum of money and paid round deposits for the whole of the olive-presses in Miletus and Chios, which he hired at a low rent as nobody was running him up; and when the season arrived, there was a sudden demand for a number of presses at the same time, and by letting them out on what terms he liked he realized a large sum of money, so proving that it is easy for philosophers to be rich if they choose, but this is not what they care about. Thales then is reported to have thus displayed his wisdom, but as [20] a matter of fact this device of taking an opportunity to secure a monopoly is a universal principle of business; hence even some states have recourse to this plan as a method of raising revenue when short of funds: they introduce a monopoly of marketable goods.
In the FWIW dept, Jared Woodard of Condor Options recently earned a PhD in Philosphy. As noted in a different post, his tiny CTA - Clinamen - isn't doing very well, but maybe Condor Options and volatility research pays the bills. http://condoroptions.com/about/