I didn't understand how this connects to the first paragraph at first, but I think you're saying this playthrough is an analog to someone making such documentation, thus saving DF from such a fate?
The general point is certainly true, there's a lot of projects out there that never see as much use as they could, where someone has put a lot of effort into the work, but never managed to present it in an accessible way - where you can't even tell what problem it's solving, even if you're dealing with that problem at that very moment.
No documentation is one obvious way this happens, but there's also lots of projects where there's a good amount of documentation but only at the wrong abstraction level. It's easy to get lost in the implementation and document only the minutiae, but taking the small step to imagine your past self, go back to the big picture, and write just a few paragraphs from that perspective, can make a project so much more usable for others. (It's also ok to just create something for yourself and put it out there in a "take it or leave it" way if you're not charging for it, this is more about the projects that do want more people to use them, but just never manage to present themselves in the right way.)