The only way that a person seeking employment can set his own wages is if he is absolutely necessary for the company's continued existence. In other words, he's approaching the employer from a position of power. When you make statements like "You're allowed to charge however much you want for your time (except for below minimum wage)," you seem to be assuming that most people won't get laughed at when they suggest that an employer pays them a wage that they can support themselves and their families on without having to struggle.

The average person does not approach a potential employer from a position of power. The average person is really an extremely replaceable cog in the corporate machine. Companies know this, so in general, companies say "You want to work for us? You'll take the meager scrapings we're required by law to give you. If we could, we'd pay you less. Everywhere else you go, you'll get the same treatment, so take it or leave it. We don't care."

That's what I mean by race-to-the-bottom wages. What's more, companies have more capital available to them, and are therefore more mobile than the average person. Now, not only are we competing for shit wages, but the company knows that if we complain too loudly or enact laws that make them pay us more, they can shift all of their labor overseas to a place where there are fewer worker protection laws, standards (and costs) of living are significantly lower, and nobody cares if they pay for safety equipment to reduce the odds that their factories will burn down.

Americans work harder and longer than most other industrialized nations, with the notable exception of Japan. Granted, in Japan, they throw themselves in front of trains just so that someone will realize that they exist as a human outside of work, but hey! We're not at that point, yet... but it's not for lack of trying. Regardless of your opinions, humans are allowed to have a meaningful life outside of labor; a living wage is supposed to provide that. You work, you kick in your share to keep humanity going, you get to have a life outside of work. Nothing about that involves "living like a king."

"Fair share" is, granted, fairly nebulous, but it's a valid concern. When a vanishingly small proportion of the population is taking all the income gains and has all the wealth, it's only reasonable to assume that they will also bear the brunt of the tax burden because there's nobody left with taxable income to pay into the system. These are the same people that keep lobbying to reduce their tax burdens. When they're not paying either, everything falls apart.

If you don't want us to tax the uber rich more, then you have to convince shareholders and C-level executives to pay out to their workers more. That's the only way you'll be able to broaden your tax base without causing rebellion. The biggest reason that they don't do that is because both the laws and the people are so over-focused on short-term gains (greed NOW!) that they neglect the long-term benefits that would actually come with paying people a reasonable percentage of the wealth that they generate.