When I need to write distraction free I open a fullscreen Vim terminal window. I copy the pages into a more shareable format after I draft them in plain text.
Maybe a word processor is just a tool and if it's useful and gets the job done, no matter how "outdated" everyone else things it is, why bother to change?
I would argue that perhaps he wants to focus on writing and not perpetually learning new tech but lately writing seems to be lower on his priorities. Glad I never got sucked up into the books - as good as they are; it's pretty apparent he really doesn't want to finish them which is a shame.
That's the distinction with which everyone is being bogged down.
George R. R. Martin is a storyteller. There's a difference. Stephen King is a writer. Michael Crichton was a writer.
Crichton summed up what it is to be a writer in the most simplistic and eloquent-in-its-brevity language I think I've ever heard: "If you're going to be a writer, then you have to write. You have to wake up every day and sit down and write. Can you imagine if a pilot woke up one morning and said, 'I don't feel like flying the plane today.'"
Basically my point is, just because someone is not adding titles to their bibliography every year or so doesn't mean they're not doing the act of writing every day. In fact, there are many references online to the importance Martin places on writing every day. And in fact, he has published things since his last ASOIAF book.
To try to say "This man is not a writer because he hasn't released the books I want to read" feels kind of silly to me.
DOS was dominant between 1981-1990. I lived through those days and remember them fondly.
In 1990, Windows 3.0 happened, and the world changed.