Imagine if we took all technology advice from 80-year olds.
Second, he runs a $300B USD financial and industrial conglomerate that he's assembled in a singular way in the span of his own lifetime. Maybe he has insights that are worth something.
Third, Kernighan is over 70. Ritchie would be, too. Knuth is 76.
I mean, I have no illusions about changing your mind, nor do I care. I just don't want anyone who is reading your comment see it go unchallenged.
He's saying the same thing that Benjamin Graham would have said: Bitcoin isn't an investment, it's a speculation like art. Sure, you could make some money on it (and some have for sure), but don't delude yourself into thinking you're making a sound investment.