Most people don't use currency to store value. Their value is stored in stocks (not bonds) retirement plans, real estate, gold. Those instruments have value independent of currency. They do keep some petty cash stored in a bank, virtualized, lent out for others to use.
It doesn't surprise me that he predicts the downfall of bitcoin. A more apt description is that he HOPES for the downfall of bitcoin and all other crytocurrencies as it means that banks will lose a ton of business and control of the money.