The primary purpose of income tax (unlike, say, the cigarette tax), isn't to reward or penalize people for making less or more money. It's to generate revenue for the government.
In last night's debate, my son's stance was that financial transactions were win-lose, and that in order for the 1% to get rich, the 99% had to be worse off. Therefore it is right to "penalize the 1%".
Louis CK seems to pose a counter-case to that logic. I'd argue that most, if not all, voluntary financial transactions are win-win. So "penalizing" is not appropriate. The 1% aren't inherently evil just because they are in the top 1%.