Besides that - income levels are talismanic, not rationally calculated. In a culture that rewards narcissism, narcissistic income levels need no other justification. Someone has to have them, and since it's narcissism and not talent that's being rewarded, the reward is based on notions of the inherent specialness of celebrities and CEOs, and not on anything more substantial.

You won't get support for progressive taxation until this narcissistic mythology is replaced by a mythology of cooperation, empathy and social awareness - which sounds unlikely now, but is a possible outcome if the current system implodes in a memorably horrible way.