It doesnt look good to seek financial independence on the basis of adopting tax avoidance tactics. This will be an advantage that marks the individual out as 'rich' and 'high earner'. It seems uneasy for the British monarchy to associate itself with using your money and status to avoid contributing to the public purse. It doesnt indicate solidarity and public spiritedness that the hereditary principle should be promoting. To be blunt, this looks unethical for a Prince of the Blood, a son of Great Britain to use tax specialists to maximise income. However, now that he will no longer be a full time working royal, he can be relieved of this responsibility to be above commercialism and economics.
Again this not a nefarious tax avoidance tactic but a very standard business practice in the US. The vast majority of companies are incorporated in Delaware unless there is a very compelling reason to incorporate elsewhere.