Well Warren made his money off of traditional investing. Naturally he would be skeptical of anything that doesn't fall within the realm of the ways he's made his money, which cryptocurrencies are definitely outside that bubble. It's hard to imagine, even as a savvy and critically thinking investor, he would look at an asset like this other than a what he's generally said. But his Rule #1 is Invest in what you know. He simply does not know this asset class, thus he won't invest. It looks riskier than he's willing to be, it's something he doesn't understand, and he's admitted that's all it takes for him to not want to invest in something.

It's a fair argument, but not one anyone will listen to, when the reward vastly outways the risks and people want to be apart of this emergent marketplace (assuming they keep their investments appropriate as always). The trustless aspects of cryptocurrencies speak to a lot of what's wrong with the current financial system, and where people would like to see it head. Warren isn't into it on that level, he's just asking for their earnings like it's a company, and is like "oh it's a decentralized whose-a-whatsit? No thanks." He's not going to get it, and he's generally a bad source for people to go to for broad crypto-market analysis IMHO. His opinions on traditional markets would be very appropriate to seek.