“Great documentation is written by great developers.” Well...this is occasionally true. Not all great developers are great at communicating their knowledge. Docs from the developer are most often a good starting point for someone who knows how to structure and communicate that information.
Considering how most software products developed by engineers suck (read "Why Software Sucks...and What You Can Do About It"), giving engineers tasks of writing docs positions the complete SDLC for disaster.
I'm not a developper but I write docs better than the devs I work with even though I had zero programming knowledge prior to this job. This is such a skewed view of things.
Great presentation! The only thing I can't agree is about Reference docs. They MUST be generated automatically. Usually, there's huge amount of formal data that must be synced with source code. It's practically impossible to keep this in sync by hand. The English text is written by people; they create templates and documentation preprocessing tools fill out the necessary forms, e.g., tables, or create graphs and diagrams.