Earlier quoted context omitted.
I think I agree with Carmack on this. I'm hyper aware of case now, but this was probably the major cause of errors for me when learning (didn't help that tooling was less good then, so there were no linters pointing out my errors).
I guess for me it's one of those things I got tripped up on initially but came to appreciate later. It taught me how to be more precise about characters and reasoning about them in code. There's also cases where case sensitivity should matter in naming in my experience, and it's not possible without it.
I'm really curious, do you have any examples? I can't think of any that wouldn't be better served by using the type system.