Dan Brown is the quintessential example of a horrible writer who is nonetheless successful. By any measure his prose is terrible. His fact checking is nonexistent. (In the first book, the hero looks out the window of a bathroom in the Louvre towards the Eiffel Tower, and you can't see the tower from there.) ...And yet he is a good tale-spinner and excellent with "and _then_ what happened?" plot, so it works.
One very successful fiction writer pointed out to me years ago that fiction can rely on several items: voice, plot, character, setting, etc. So "being a good writer" is just an overall label that obscures those things. Ideally an author is great at all of them, but few are.
And as the same author pointed out, if you write (and want to make a living at it), you have to publish, and you have to get noticed. There's an old saying that books don't become bestsellers if they're hidden in a trunk. In the olden days when book publishers ruled the earth, an author could rely on the effectiveness of a good agent or publisher (and the luck involved in finding one). Now, the author has to learn to present herself with confidence, which does not necessarily come naturally. It becomes another relevant skill that has little to do with plot, character, etc. -- rather like the skill of getting your own butt into the chair in the first place.
That does indeed map to tech skills. Just as a thoughtful writer (and reader!) identifies the various parts of the novel, so too does a thoughtful developer consider her tech skills (idea generation, debugging, team building, whatever). And the ability to communicate/market is among them.