> beginning to suspect the developers aren't interested in moving it forward, or even properly maintaining it

This will be true of all systems. Devs hate adding comments, writing documentation, maintaining tasks/wikis/etc., and everything else that we need them to do. Some people try to make them track their time, which I think is both pointless and unlikely to happen.

The only solution to this is to move it out of the "discipline" column and into the "process" column. For example, I set up git hooks so that a commit will be rejected unless it's tagged with an issue number. And then I have another rule that says that issues aren't accepted unless they have the important fields filled out ("steps to reproduce" for a bug, "user story" for a feature).

It's not perfect, but it definitely creates better habits overall.