If it were simple, why is there so much debate? There is much more to this than capital gains laws.

Yes, when in Rome... However, that applies to conducting one's interpersonal behavior. If my private assets are not in Rome, what then? What if I become a Roman citizen? Does Rome then have a claim on those assets held in other countries? Who owns me: myself or a government? How, why and to what extent? Not as simple anymore.

Does it make any sense for a business operating and generating income exclusively in Singapore to pay taxes to the UK government just because its owner is a citizen there? Should a German national having his savings at a bank located in the UAE be subject to an account seizure by the FCTO? When a US citizen owns property in Brazil, what right is there to any share of the property by the owner's government?

There's a boggling morass of compensation clauses in tax legislation around the world that have been produced under the guise of "fairness" but primarily result in politicians getting their cut no matter what actions they choose to pursue or whether it's the will of the people or not. If these taxation activities had not be legitimized by those in power, they would be considered extortion and fraud.

People tend to conflate morality with ownership: if one person has more than another, that must be "immoral" or "unfair" simply based on the disparity. Not paying your "fair share" is blindly assumed to be reprehensible, but according to whom? There is often no examination of the process by which the assets were obtained. It's a focus on quantity (of assets) to the exclusion of quality (of owner).

An individual investor might diversify across various sectors (agriculture, finance, mining, etc); a company can do the same, diversifying across various regional jurisdictions. The protection offered is the same: distribution of risk - if one region becomes hostile or unprofitable, there are others that can provide a way to survive and thrive. Corporations have been internationalizing themselves for ages. This is not caused by loopholes; attempts to artificially and forcefully control investment leave those loopholes as incentives to keep capital from fleeing entirely until it can be trapped and the loopholes closed, solidifying control and an exclusive power base (this has been the pattern for every empire and today's governments are following the same path).

Individuals can internationalize the same way as corporations do. If all of a person's assets and investments are in one country, such as Argentina, and people are forced to keep their money in a risky economy, the chances for losses are greater and the incentive to make use of that money domestically is reduced. This is the same response companies have to politicians' perpetual desire to do dumb things, and there's nothing preventing the individual from protecting himself the same way. It is the most effective form of wealth protection possible.