By this logic, why doesn't every successful Bay Area startup just up and move to Dubai?
If a few rich assholes want to live in Dubai, fine by me, but the successful companies are always going to be where the skilled people are. Skilled people are where the infrastructure (education, health) is best, and you have to pay for infrastructure; that's why taxes exist.
Finally you can afford some nice things, then suddenly you're taxed at 95%.
Define "nice things". For me, "nice things" are good books, cool technologies, travel, challenging problems to solve, and interesting company. None of these have to involve luxury goods. My point is that we'd be taxing people based on what they buy, not their income. In other words, the tax is based on what you do with the money, not how much of it you make. If someone gets rich but is using his money reasonably, he pays reasonable taxes. If he wants to belch tons of CO2 into the air by flying around in his custom-built jet with a swimming pool in it, like a lot of the uncultured mouth-breathers in that set, he'll be very highly taxed for it.
Besides, those among the rich who are ascending Society and flying around in private jets are too busy schmoozing and colluding to be building anything useful, just as authors who get sucked up into that high-society shitfest stop writing readable work. (Hard to write anything valuable if you're constantly coked up.) At this point, they effectively ought to retire. If we discourage them from being here, great! They're already past peak, and now they're just taking up space at the top. Their exodus makes room for people with talent and energy.