General wisdom in author circles is that you write THEN edit. Having spell check and other tools only hampers the creative process.
Darkroom/WriteRoom (and the dozen+ similar programs created over the past decade or two) http://jjafuller.com/dark-room/ offer zero nonsense, zero setting, zero hassle, text entry programs geared towards authoring a book. They get rid of pretty much everything on screen except for text and background. No UI, no features, nothing. Just the way it should be.
I've used them for NaNoWriMo for years and years.
Survivorship bias, sure, but if his writing machine has lasted this long, it's well on the "will last even longer" side of the bell curve.
His editor and publisher can still use the modern tech to do whatever it is you kids use these days to blog your books.
Quality of writing, to me, is a more important trait of an author than volume of output. It would be nice if he got moving though.