In my opinion, Warren Buffett hate bitcoin because it's a way for many ordinary people that without trading knowledge become rich.
He thinks he is big and wealthy, most successful in his work and now some kids get rich overnight thanks to bitcoin

He is trading on the stock market whole life and become no. 1 and I don't think he is willing to change, understand and accept new things.
So damn true. Imagining you've spending all of your life, experiencing a number of times on the verge of bankruptcy to become so called "legend investor". But some day, many people of your grandson's age become millionaires or even billionaires without any knowledge about finace. How unfair! I think jealousy is the main reason behing Buffett's hatred on bitcoin. He can't stand the fact that many many people are becoming rich from bitcon.