That's a pretty strong statement about everything else in git.

I mean, that's also pretty easy to fix:

#!/bin/sh
# git-mcommit - commit with a default message
exec git commit -m "$(git diff --cached --stat)" "$*"

Yeah, but the problem is that people build workflows around commit messages. So you get a git log containing "Just committing this for the evening" and "FUck, I think this was right? Lemme send it to you" but then people want to take those events and process them. We need to have *merge* messages