[geofft]

The offsite copy involves trustworthy people, and unlike with data, there's no client-side encryption for gold.

If you do believe that the NY Fed, the Bank of England, and the Bank of France are "above reproach," then your argument is absolutely correct. But if you can't be sure of that—and this article is definitely attempting to cast doubt on that—then there's the usual argument about self-hosting. Amazon's probably a better sysadmin than most people are, but you're the only sysadmin that you have meaningful control over the competence of.