Right now, we punish people with higher tax rates when they make the positive choice to work harder and earn more. Defenders of the status quo might argue that earning income at a subsistence level is a necessity, not a choice, so it is rightly tax exempt -- we exclude the first $20,000 or so (or more, depending on your family circumstances). But if you choose to earn a higher income and bring home more than you need for a minimal standard of living, you pay taxes on those extra earnings with rates that increase along with your income."Now let's get cracking on that estate tax repeal!"
People who earn more work harder, and you would earn more if you chose to. This should be engraved in marble as the perfect expression of the right wing jerk-off fantasy version of how the world works.