It's expensive being well off. If you make $250k a year, you take home $159k in SF. A big chunk of that goes to cost of living such that the $20k means one of your two kids can't go to the college they want because it's $50k per year, and you don't qualify for financial aid.
And others that aren't, that's the point. That kid can't go to his college of choice because it's expensive, not that he can't go to any college at all.