And there's the whole hidden philosophical underpinning that slips by in virtually every political discussion regardless of your leanings.
Is the money a person has rightfully his? That's the whole question the Black Lives Matter person is instinctively getting at, and what all liberals are getting at when they support measures like increased progressive taxation. With the huge decreases in pay with increasing hours (the "big economic squeeze") concurrent with extreme gains in wealth and income going to the top few percent, anyone with a sense of justice can see the problem for what it's worth. It's only people like neoconservatives who think the cash the rich (and especially the super-rich) have is justified.
So yeah, many members of the rich class aren't entitled, ethically, to the money they're making. Ethically, speaking of what a person should make relative to his actual work, things are very different than how the market works, which is purely according to demand. Poor people should be getting more money; the whole phrase "the working poor" shouldn't even exist. They're the ones working their asses off and getting crumbs while the super-rich are bogging down aggregate demand by not even being capable of spending the money they make.