$250K isn't that much money.
And consider the lifestyle one has set up for themselves...they probably have long term obligations due under the idea that their income wouldn't be reduced.
If you got a job making $250k, bought a nicer house, nicer cars, etc. Then you develop that lifestyle. If a tax increase reduced their "take home" income, then why wouldn't they have to tighten their belts. No, they are going to move to the slums, or buy an old clunker, but they will have to change their spending habits, thus tightening the belt.