Carmack can be enthusiastic about AI because it's no threat to him, he's already set. He's not going to be laid off, and if he is, he can just do coding as a hobby for the rest of his life. He doesn't need to worry about what blue collar job to retrain for in middle age to be able to pay his mortgage and clothe his kids.

And it is a form of cheating to take a gift and profit off of it, keeping all the profits for yourself, it goes against the spirit of it. Until now that was fine, because there was a sense that it made more things possible and created jobs, and these projects were improved through reciprocal contribution.

AI vacuumed everything up for itself and turned around and said now I'm going to replace you.