Buffett has always made it clear that he will steer clear of investing in anything he doesn't understand. He didn't invest in Amazon for that reason and look at Jeff Bezos now. I wouldn't pay Warren too much attention if he doesn't know a lot about the industry/ company but I would pay special attention when he does. In the case of Bitcoin you can disregard what he says. He said himself he doesn't understand the value of it. He didn't of Amazon either.
RE: Daily: Buffett calls Bitcoin "Bubble" / Intel working with Ledger / Chinese Exchanges