I guess that's somewhat true, yet the upper middle class only got stronger and stronger, which seems strange if they were all fleeing the jurisdiction because of high tax rates. It seems much stronger evidence that it's not a real threat that should concern the country - most high income Americans are reasonable and understand that we need to pay to maintain all this modern stuff we have, and hopefully improve upon it. It wouldn't seem to be a major concern if a small, selfish minority decided to pay the exit tax and go somewhere else.

Netherlands has a wealth tax system, just for reference. I agree with your 1. point