INCOME TAXES AREN’T DRIVING AWAY THE HIGHEST-INCOME HOUSEHOLDS.
If high income taxes were chasing away rich Californians, high-income households would be more likely than low-income households to move to states without income taxes—but they aren’t. How come? States without income taxes are cheaper than California in other ways—housing costs, for example—that matter to all types of households, not only to those with the highest incomes. In other words, California does lose people to lower-tax states—but not just because of income taxes.
That's from a report by the Public Policy Institute of California. In some ways if you look at the full report (which I recommend you do) what you get is everyone's leaving California. But if you have to live in Nevada instead, I feel sorry for you, and some ice is in the mail. After all, one assumes you get something for the taxes you pay to a state.
So, my guess is that if you're rich, you might want to stay in California even if you have to pay a bit more in taxes. Here's a bit of what you get for those taxes, and that's even before someone goes to school or gets saved by a firefighter or borrows a book from a library: