At least, for writers trying to submit electronically to markets. Micah explains the problem.
For markets that take paper submissions, submitting in Standard Manuscript Format is not a big deal. You can use whatever wacky production process you like and print the thing out. Done. Heck, I even wrote an extension to Sphinx to produce sffms-latex from reStructuredText. It even works! Mostly.
But as time goes on, this “analog hole” will go away. As electronic Standard Manuscript Format becomes the defacto format, all of us crazy hippies really will be forced to use Word. For reals. Or possibly Scrivener, which does a pretty good job of exporting to Word. Actually, come to think of it, that doesn’t sound too grim-dark, does it? Although I do have it on good authority that Scrivener creator Keith Blount sustains his decaying body by sitting on a great cybernetic throne and draining the life-energy of a thousand psychics every day. So there’s that.