Rich guys threaten to move whenever any state suggests raising taxes, and of course our numerous publications dedicated to presenting the views of rich guys type it up.
If you are rich it is trivial to spend 183 days in another state to establish residency. I don't think any state should care if these guys move, but the fact that they get loud and lobby against this stuff shows that, surprisingly, most of these guys don't want to move to Tallahassee.
California, specifically, is already a very high tax state and somehow they love it and can't leave. Weird.