... you read an awful lot into that comment, I think you are being a bit uncharitable.

Though I agree with many of your points, what I think the OP was gesturing at was the idea that billionaires are more avaricious than the average person; hence we shouldn't be surprised that Paul Graham is wary about paying an effective tax rate that would put him on par with majority of tax payers in this country.

This isn't an new or particularly controversial observation: e.g. "Money never made a man happy yet, nor will it. The more a man has, the more he wants. Instead of filling a vacuum, it makes one." Benjamin Franklin

"The love of money grows as the money itself grows." Juvenal

Having worked for several billionaires and seen them in their day-to-day, those quotes resonate with me.