Buffet has in general never been much into technology at all. My best guess is that he has poor tech skills. He is mostly into companies where he likes the product and is a master of using money to get more more money (e.g. insurance float). He is also very old, and WB is one of the last persons I would go to for crypto advice. I also believe cryptos are more kind of commodities and going to be used in barter trades, so I guess many people focus too much on Bitcoin being money and miss the point. His best friend, Bill Gates, is very bullish on BTC though.