You said it yourself: he was primarily a professor, not an artist. His position being a "luxury" is another argument. Anyway, He taught languages to brilliant students and created a highly respected translation of Beowulf. LoTR, Silmarillion, Hobbit, and all of it, were his hobby, a secondary but burning passion.

I'm sure many on this forum have secondary passions, be it music, visual art, writing, or anything else. Yet most of us realized we need to make money, and that those pursuits can be done at a fairly high level in our leisure time.