I'm always taken aback by this fascination and heroification with John Carmack (or similar figures) on HN. I love Doom and Quake too, but that doesn't qualify him any more than any other random senior engineer to work on something totally different. From his interviews it looks like he understands little about the technical details of ML, or about as much as anyone can learn in a few months, and is just banking on PR…
BUT - I strongly believe, that he has earned quite some respect during his career.
And - importantly in this case - he is well known for NOT blowing things out of proportion, indulge in wishful thinking, hyping up unrealistic expectations or jumping to premature conclusions. He usually knows what he's talking about.
This is not people blindly believing everything he says - but more a case of his statements holding up really well under critical inspection most of the time.