The focus of what Torvalds said is the concept of tech singularity. TL;DR "nice fiction, it doesn't make sense in a reality of finite resources". I'll move past that since most of the discussion is around cryptocurrencies.

Now, copypasting what he says about cryptocurrencies:

For the record, I also don't believe in crypto currencies (except as a great vehicle for scams - they have certainly worked very well for the "spread the word to find the next sucker holding the bag" model of Ponzi schemes). Nor do I believe in Santa Claus, the tooth fairy, or the Easter bunny.

For those who understood this excerpt as "Tarvalds thinks that cryptocurrencies dant ezizt lol lmao": do everyone a favour and go back to Reddit with your blatant lack of reading comprehension. When he says that he doesn't believe in them, he's saying that he does not see them as a viable alternative to traditional currency. (He does not say why, at least not in that message.)

And for those eager to babble "ackshyually ponzi schemes work different lol lmao": you're bloody missing the point. He's highlighting that a large part of the value associated with cryptocurrencies is speculation, not its actual usage. Even cryptocurrency enthusiasts acknowledge this.

I apologise to the others - who don't fit either category of trashy people I mentioned above - for the tone. Read the comments in this very thread and you'll likely notice why of the tone.