Private property is just as coercive as taxation in the first place. You do not have a God-given right to make hundreds of thousands of dollars by investing millions of dollars and pay nothing towards the upkeep of society. Basic freaking social contract theory, and, in fact, basic law: financial instruments and corporations could not exist as they do except by government fiat.
Second, yes, he will make the sacrifice if everyone else does it. That's sensible. You don't solve large-scale systemic problems by individual action, not even mass individual action, but only by collective action. Again, this is just how the world works.
When did anyone ever get asked if they consented to the "social contract"? No one. We need, at the very least, to change the term. Something like "social compulsion", perhaps?
The person creating capital may not be someone who is liked, but they often produce jobs, and products/services that people want. Their capital comes about because of voluntary transactions within society. The so-called "social contract", meanwhile, is built on coercion.
But if I don't consent to the "social contract" called private property rights, then your exercise of the rights that you've claimed that I don't recognize seems equally coercive.
I happen to believe (in agreement with you, I think) that private property rights look more useful (in a benefit-to-humanity way) than the rights that most people who use the term "social contract" think of, but I don't believe there's a clear philosophical difference between the two.
Private property, financial instruments and corporations are also built on coercion. Literally, they all exist by government fiat.
You can tell yourself whatever Rothbardian fables you like, but the only real business you're building without any participation in a modern, "coercive" society is a subsistence farm.
You are correct that government currencies exist by government fiat. Who said that those had to be the only currencies? Of course government does mandate that its currencies are recognized as legal tender, but that's something that governments get away with across the board.
Corporations are indeed creatures of government. Are they required to conduct business? No, but they are awfully convenient, and allow for a lot of rotten things to occur.
Private property? If it requires government's nod, it isn't private. And, of course, we see this all the time, when government decides that it wants someone's property, and takes it. It might be your land, your automobile, or something else. It is all up for grabs.
Not sure why you're name-dropping Rothbard, but it doesn't help you here. No business is going to exist without participating in the existing society. Trade and commerce require cooperation. The alternative is what brings a society closer to subsistence farming (and it tends to leave people starving).
That's a bit of a strawman, since I said nothing about the securing of property. As you are undoubtedly aware, government does not allow a choice in this, but you're likely taking a position that it must be this way. You're also taking the rather weak stance that existing precedent doesn't allow for any other way. That kind of thinking serves governments well (they don't think well outside of the box), but not private individuals and groups.
No, I'm taking the stance that bourgeois governments are the result of a long historical process whereby the mighty displaced the weak and stole their property until there was eventually only one ruler, who enforced the property regime of their liking.
Something to that effect has undoubtedly occurred. I think that things can work differently. Do you?
We've had a chance to see a number of government experiments run their course (some continue to), ranging from absolute monarchies, to Marxist-Leninists, to Maoists, to various kinds of republics. All of them have ended up going in similar directions, over time, consolidating power, though at different speeds.
It's not as selfish as you try to spin it. There are any number of political and economic policies that you might favor, but that only make sense in aggregate.
I might favor more NASA funding, but I'm not going to write a check and donate to NASA. That doesn't make my desire for more NASA funding any less earnest than someone who wants less funding for NASA.
Not sure if selfish quite captures it. It's more practical consideration. I'll give you X, if everyone else is also giving you X. Otherwise, my X won't make any difference.
Looking at again: it's a variant of the prisoner's dilemma. If everyone moves, nobody is worse off. If you move on your own, you are worse off. If everyone else moves and you don't, you're best off.
Unsurprisingly, the dominant strategy is to write blog posts saying "we really ought to amend the taxation laws" :D
So if he wants to pay more tax, he can.
He may also rearrange his tax affairs to increase his tax liability. Same thing, but with the exciting frisson of potential coercion (gosh!).
He doesn't seem to be doing either of these, however. Possibly because that might lower his social status vis-a-vis others of his kind.
So actually, he's prepared to make a great personal sacrifice ... if everyone in his class does too.
It seems less impressive when you put it that way, but that's human nature.