no, not his main business, but the company he is going to invest. He didn't want to invest to something he didn't understand. And he didn't like tech companies because most tech companies produce digital product as main business.
Tech companies that sold physical product: Phone manufactures, telecommunication company, etc.
Tech companies that sold digital product: AWS (amazon), Firebase (google), facebook, etc.
And tech companies has somewhat complicated core business for a non-tech people to understand. That's why buffett didn't like or isn't interested in investing to tech companies.
And in crypto, most of its core business is digital, which is why, for some people, it looks like it doesn't have any purpose, doesn't produce anything, doesn't provide service etc.
In the contrary, more and more job opening for a blockchain developer is available in my country (from what i've seen in a popular job site here). Indicating that people start realizing the potential of blockchain (as a developer / business owner, not trader)