"Fairly" is begging the question.

"Discriminatory" isn't necessarily a bad thing, and needs to be further refined if it's going to be meaningful. Progressive taxation (in isolation) does not discriminate between people. It discriminates between dollars. My first dollar is taxed the same as your first dollar; my ten thousandth dollar is taxed the same as your ten thousandth dollar; my millionth dollar is taxed the same as your millionth dollar. It is true that my millionth dollar is taxed differently from my first dollar, and that is discrimination between dollars, but generally people don't hold "equal treatment of dollars" as a moral principle.

"I can't imagine the arrogance necessary to think that you know how much to tax a certain segment of society relative to another."

Roughly the same arrogance necessary to think you know how much to tax in the first place, or really any other decision making on that level.

The part that you're missing is that progressive tax is still regressive in terms of marginal utility of the taxed income. People look at percentages or dollar amounts when what we should look at is the utility of that dollar.

If I am paid $50,000 a year, let's say I get taxed around 30% (including the plethora of other gas/sales/alcohol/property/SS/medicare taxes I pay). That means I lose $15,000 a year. After rent, food, clothing, and life's other expenses, I have maybe $10,000 a year in disposable income.

Think about that - I get taxed more than I have available in disposable income. That extra $15,000 I pay is a SHIT LOAD to me. It means drastically different lifestyle changes. It means living somewhere clean and safe versus living in a crime ridden shithole. Paying for kid's college in only a few years. Being able to actually afford private health insurance. The value of $15,000 to me is thousands of times more valuable than $10,000,000 a year to someone making $20,000,000 a year. That's one less mega yacht, per year, for someone like that. You are not taking much of value from them when they already have everything.

And despite that, you still think it's unfair? Quit getting caught up in dollars if you want to discuss fairness. Look at the value of what you take from people.