I like this. This makes a lot of sense to me. If it managed to gain adoption into major distros, it would be incredibly good, though obviously that is a longshot for a lot of reasons.

If you really want it to get adopted into major distros, the best approach is probably to convince the systemd folks that it would be a great addition to their package ;)

edit: A bit of constructive criticism. I really like the concept, but I think the way that package managers are supported could be improved. I think it would be better if all of the handlers for a given package manager were in the same file, instead of having them spread across every file. There's obviously lots of ways to accomplish this.

Also, as it is now, this project does not seem to use a ton of things that require C++ - you could shave some binary size cost by converting it to pure C.