Relatively speaking.
Why won't you be consistent and apply the same to tax rates? Everyone should pay an equal amount of MONEY regardless of their income level according to the same logic.
My proposal is just very draconian, I agree, and I'm not sure it would work - but there's some degree of fairness in it. You need incentives. Plus, you're a liberal and actually in favor of progressive taxation I presume, so why wouldn't you be in favor of this?