I found this: http://www.theverge.com/2014/5/14/5716232/george-r-r-martin-uses-dos-wordstar-to-write
First thought: I my god! Second thought: He is right!!
Let’s see it from his perspective. He wants a machine that focusses on text production. Why on earth does he need a graphical user interface?? He does obviously not care about WYSIWYG because the process here is focused on pure production only. No formating, no printing. He reduced the work environment to support the process at its best.
I had to think on diving computer again….