[chipotle_coyote]

A whole lot of people don't like writing in Microsoft Word, for a variety of reasons, and there are editors of varying types aimed at that audience. A lot of professional authors write in Scrivener. I know of more than you (apparently) think who write in Ulysses or iA Writer, which are both pretty capable editors. I own all three of those apps, am actively using Ulysses for a big fiction project currently, and don't own Microsoft Word. I know of more than a few fiction authors who like writing their prose in text editors -- Charlie Stross, Cory Doctorow, and Steven Brust come to mind off the top of my head. (Brust has used Emacs for a very long time and I presume still does; Stross and Doctorow both used BBEdit at some point in the past, and I believe both used Markdown, although that was years ago.)

As for whether Markdown is "a bit of a joke in the real world," I suppose it depends on what your definition of the real world is. Having attended a major technical writing conference a few weeks ago, I can assure you that while there are arguments in my field over Markdown, they are not over whether we should just give up on it and use Microsoft Word instead.