It makes no sense because you're choosing to not think about it.
Person A works in a factory. He works hard all year building products and at the end of the year he has earned $50,000.
Person B sits in front of his computer at home and moves money around in the stock market. One day he gets lucky and makes $50,000. He then decides he doesn't need to do anything more the rest of the year.
Under our current system, Person B is rewarded with a lower tax rate and Person A is punished with a higher one. Person A is punished for working hard all year and building products.
How long before Person A stops doing that?