Linus's expertise in programming OS kernels in C doesn't translate very far. It went far enough to make a fast implementation of a distributed version control system designed by somebody else, but not far enough to make an accessible command-line interface for it, or a reliable storage engine.

(TIL that my git repository at work is corrupt. Again. Second time in two years. "git fsck" thinks it's fine. "git repair" spins forever. Thinking hard about Fossil just now...)

We might reasonably guess that he is dead wrong about the merits of C++ as an implementation language. Observationally, he would have plenty of company.