hmm, I thought you were talking about writing manuals, documentation, etc, along the lines of wikipedia's interpretation of
Technical Writing. I think that field is less in demand than it used to be, as technology gets more accessible to people who don't read manuals.
If you were talking about writing articles that might appear in Wired or Slate or ****tier versions of the same, then yeah I agree, if you're not already writing well for its own sake then you're probably not going to make it.