Here's one of the reasons why I'm a monarchist.
In the treatment of their minorities, the Chinese government are amoral scum, make no mistake. But democratic governments, prone to be dictated to by their own economic interests, tend to ignore moral issues.
Charles may be verging on loopy, but he couldn't care less about popular opinion in matters economic. So he can criticize the Chinese government and there's nothing anyone can do about it.
God Save the Queen indeed.