Brings up some valid concerns, but ends up in just another circular goldbug argument. If free market is allowed to choose money, it must be gold because it's always been like this. Well, that's wrong because there were money BEFORE gold: cattle, cowrie shells to name just a few. So, at some point gold displaced those earlier money and came to dominate because it was a better fit for monetary function.
Another away to approach is to apply their logic to other areas of economic choice.
"If the free market is allowed to choose forms of transportation, it must be horses because it's always been like this."