I think one of the disconnections here is that you are talking about extra cash (over what you currently earn), whereas rgbrenner (and probably others) are talking about all income.
And I think they have a point: $100k is a lot of money, but what if you got sick and couldn't work anymore, ever? Wouldn't you be at the risk of starving or becoming homeless if you had to stretch that over 30 or 40 years?