But this is a personal project. Something that is unrelated to his job. So it doesn't really matter what "bar" it is because he's doing it for his own benefit, not Tesla's or "humanity's".
Unless you're implying he can't have personal hobbies anymore. Which was the exact point of my previous comment.
I'm saying that there is a bar and it's higher when lives depend on it.
There is a long list of activities that people could do in their personal time that would be considered inappropriate. What is done outside of work is relevant. It can form part of a character assessment which can have political and legal ramifications.
If Tesla ends up with a dangerous product then it becomes very relevant.
At least you've made it perfectly clear that you don't think people should have lives outside of work. Hope you also subscribe to the same ideology yourself and don't have any personal projects or hobbies (why are you on HN anyway, shouldn't you be working right now?) or else you'd easily be considered a hypocrite.
Either you're misunderstanding logic, law or society. If Karparthy fails he runs a real risk of having his life very closely examined. The rules are different for different people.
I do machine learning medical work for the coronavirus. I work at near optimal as humanly possible. Occasional hackernews is one of my few indulgences.
By your logic, you should have no indulgences, so you should probably stop posting.