Fourth, this indicates the conservative nature of most wealth ownership. There is, of course, no productive value to gold, but the owners of this wealth do not care about that. What is of concern to them is the preservation of their status, indicated by wealth, and that is what motivates this decision.
Fifth, this does very clearly indicate a capacity to tax wealth more: if the wealthy cannot put their wealth to productive use then they might as well pay tax with it.
That people try to preserve their wealth shows that it should be taxed away from them.
That you resist the mugger shows your wallet should be taken.