I hear what you are saying, but think a more interesting case can be made for items that are (a) fungible and (b) accepted as a medium of exchange.

Ownership of gold in a vault would be a good one to critique, although I suppose you'd have to find some way to pay for the transactions.

If gold fails this test, then I can't see any point in using a blockchain for any store of value but simply as an in-and-out mechanism for transmitting money.