I've been trying to get into modding and I had an idea like that when I found out how to do it. But I am not someone who can commit to that kinda thing. (And there are already enough modders who don't finish mods)
Tbh I think that most mods are unfinished because most people just want to try things out, and then quit making it when they have no more ideas.
Then again it's easy to lose focus/interest or just completely don't feel like it or forget about it, or plainly having no time to do it.