I think you're wrong mate.
Lets run with an example, it's on a smaller scale, but the principle's the same.
I have a fictitious 100k burning a hole in my pocket, but don't need to spend it so have quite a few options, some of which are :-
- Invest it in something in the UK and pay Income Tax on it, and / or CGT on any profits
- Stick it in the bank, receive bugger all interest and pay next to no tax on the minimal income generated
- Invest it abroad, generating a return outside of UK tax
I will only do (3) if I get a better return on the tax-free option than I'd get from the taxed option on (1). If option (3) was a poor investment, I'd be better off going for (1) and paying the tax on it. Anything else would be cutting my nose off to spite my face, and, in this hypothetical world, I'm rich, but not stupid.
The caveat to that is if the rich are worried about being on their assets rather than the profit generated by their assets then it makes sense to shift those assets out of reach of the state. The country's pretty goosed financially so that's a real concern for the super-rich.