In other words, they protect the already-rich from competition.
True, although I would amend that to "Taxes on high incomes don't hurt those that can adjust their incomes easily..."
As a consultant, I can just tell my customers, "Well, I'm going to have to raise my rate because the government raised mine..." and they'll completely understand...and raise their rates on their customers accordingly. The tax eventually trickles down to those with little to no economic flexibility.
You got it!