> Yes!! Stash has a problem that it's attractive to beginners, and its easier than other commands to hose yourself. It's a separate system for managing changes outside of commits, I don't get it.

It isn't a separate system "outside of commits". Stashes are literal commits. If you were to write a script that made little WIP commits it would probably end up looking a lot like git-stash (which is literally just a shell script wrapper around other git commands).