It's an interesting analogy. Without hearing his comments, I would have to suspect that his rationale is that bitcoin's current value is its connection to a structure that will be short-lived.
That may or may not be true. If anything, bitcoin shows that technology can provide non-tangible currency not tied to a particular nation or political structure. That has value, even in legitimate applications - such as international transactions that can be accommodated simply on the basis of bitcoin or some similar currency that does not have to do through the exchange process. The transaction is set in bitcoin and the parties to the transaction deal in terms of bitcoin - perhaps from bitcoin they have and use, or perhaps through an exchange that they handle on their respective ends without that function having to be accounted for in the actual transaction. Of course, international business has been doing that same thing with the USD or Euro for years, so that function is simply electing cryto-currency over fiat currency.
But to truly analogize to the Confederacy, I think you would have to have a basis for likening bitcoin to a short-lived nation. I think everyone should recognize that bitcoin may easily end up being a note in history, a building block upon some different future - but to say now with conviction that it is doomed is nonsense. There's no way of knowing that.