Currently there is stable version and Experimental. Looks like a lot of people prefer Experimental for new features and (surprise!) bug fixing. Frankly I don’t even sure if anyone reports bugs for stable version.
At the time Calcysm DDA develoved for almost 7 years. It become relatively popular among opensource projects. That is very relatively, yes, but still. It attracted enough contributors to have manpower to at least try diffierent strategies in development.
Despite for contirbutors it may be more attractive to implement new feautres, some (and a lot of) players prefer stability over new features. Also modding for unstable version is complicated and unstable. There is no stable platform for modding.
Maybe it time to think of different strategies for new versions?
Of course there is no man power for LTS releases like in Ubuntu, but a at certain exent some contributors might be intrested in supporting stable version.
Other opensource projecs do fixes in stable versions.
Dungeon Crawl Stone Soup, for example: