I doubt he will need to know a popular language to get employment opportunities if he's the son of John Carmack.

I doubt employment will ever matter to him if he's the son of John Carmack.

Well, I guess even some rich kids might want to make their own fortune rather than living off their parents.

My point was that he's more likely to work for himself, whether for increasing his wealth or for some other goal, than care about how employable he is to somebody else.

Ah, yes. Good point :)

Depends where he is. I started at 10 Z80 assembly programming. I still needed to know C# to get a job in Australia.

He's also apparently already taken Algebra 2, a good five years or so earlier than usual.