While I agree with you, and Warren Buffet is an old dinosaur, I don't think its unreasonable to imagine a scenario where non-government backed crypto-currencies will come to a bad end. Blockchain will have far reaching consequences besides just money and finance anyway.

Can you not picture a future where governments make tokens of their own and issue them to the non-users now? How could today's projects compete with that kind of onboarding?

Additionally, a new IRS policy will be implemented in 2018. For tax purposes, any reception of cryptos for payments is a taxable event. The tax is proportional to the current value at the time. Therefore, not declaring your crypto as taxable income will now put you in jail. This is the evil empire pretty much pegging their awful currency to our beloved cryptos, and will likely be the largest hurdle of businesses accepting for payment.

Currency IMO is one of the lamest use cases of blockchain and I think the global blockchain revolution will have a lot more socially beneficial success with secure identity, communities, consensus, and voting.