I (being the kernel documentation maintainer) have already seen an increase in activity around the docs as a result of the change - it makes things far more accessible.
It's also not really correct to say there's not much documentation. We have quite a bit if you look at it, especially if you count the 55,000 kerneldoc comments in the source itself. The quality of some of it and the organization of all of it is another matter...but we're working on that.
It is almost certainly correct that this is a contributing factor. It is unlikely to be the only factor or even the primary factor.
The very human element, that most programmers simply don't like writing documentation is certainly a larger factor. If this holds true for the Kernel no new format can fix the problem by itself. At a minimum it will require a encouragement from the top to improve.
Definitely the case in my office. A couple of opinionated and (relatively) senior devs that think the code is the documentation. No, I can't read this 40 yo fortran code and use it as the basis for a new program on a different architecture. It uses gotos and variables like "yxtgn" that mean nothing to the reader (turned out y meant it was an integer, weird). I spent a month on that because there was no documentation, which took up a page once I was done writing it after my reverse engineering effort.
And then documentation, where it exists, is often poorly CM'd word documents, and poorly OCR'd PDFs (or doc->pdf that somehow lost the ability to be searchable and selectable text, what option did they select?!?).
The offending systems are only maintainable because a few people haven't retired (< 1 year left for several of them) and sheer force of will for the rest of us.
