What bothers me is when projects have a hard dependency on something like systemd or even Ubuntu, because most of the time it is not necessary and it means I can't use it.

But other than that, as long as I can compile the project from source (and if it's done properly I don't need instructions for that), I'm fine.

I would assume that a repo providing instructions for the AUR is already better than one assuming that "Linux == Ubuntu", because the developer knows at least one distro that is not Ubuntu :-).