This is sad, not so much because of the lack of code coming from this world class programmer, but because coding is such fun, and Torvalds isn't having fun programming, else he'd be doing it.
I'm closing in on forty years of coding and still get a kick out of it. I'd still be doing it if I weren't getting paid for it. But my skills are at best, uh, modest compared to Linus. I'd think that doing a thing so much better would only be that much more fun. But this is a data point against that correlation.
Linus still authors code, just not on the kernel. He still seems pretty active on https://github.com/subsurface/subsurface and even some recent commits into git.