The chart you presented doesn't show the value created, just the value captured by a given segment. Wouldn't that be an important consideration? It's estimated that innovators, the group that Dr Graham is talking about, only capture around 2% of the value they create, with the rest going to society [1]. That's the whole point of the essay, that maybe reducing the 'absurd' levels of wealth will also lead to reduction in the levels of value creation that society currently benefits from.

[1] http://www.nber.org/papers/w10433