The problem with a tax cut for the rich or for a flat income tax/non-progressive income tax is that once a person's needs are attended to, all other income is excess and therefore, wasted.
I'm not monetarily motivated. I never have been. I've tried, but just can't make myself get all that interested in money. I like the things that it can buy (big boats, HQ booze and nice hookers) but not enough to center my life around it. My creature needs are exceedingly easy to meet, so I'll always be middling to low end income. Sad, but true.
The majority of my income is pissed away. After the amount I'm squirreling away into 401k, I keep enough to make sure I'm clothed, fed, and housed. Hookers and liquor stores get the rest.
Rich people, on the other hand, while obtaining better hookers and booze, simply can't contribute back to society on the smae scale that I do. There are only so many hours in the day, and unless they pay for booze and hookers for some soup kitchens, they'll never put all of their income back into society.
Since none of the soup kitchens I've eaten at lately have free booze or hookers, I say the rich should definitely be taxed harder. Tax them to their knees, or until they start pitching in for my hookers and booze.