Well, I particularly tend to write what I thought whenever I finish something. I'd say most people simply don't bother, though. There are various reasons. Some people do want to write something but have no confidence, some people do want to write something but simply don't bother... But I'd say most people relate writing as something tedious, really. Even if you do appreciate books or other kinds of written works, it doesn't mean that you like writing. I think that's the principle. I do believe that most people in the world dislike writing, or at the very least feel no pleasure from doing so. It's a pity, really.