Documentation often gets cited as the main 'semi-techncal' thing to do for an open-source project.

However, I disagree with the point that moribund projects could be revitalised this way. If the people writing the code have little interest in explaining to other people like themselves how to use it then IMHO writing additional text for less involved people is not going to be very impactful.

Your second point about myopic docs is spot on, though. A human-readable summary can be invaluable but it involves getting your head around what already exists first -- that requires some will from the developers in the first place.