alt Hacker NewsI think the mental model is like C vs python. Git gives you a forensic trace back in time. jj gives you a story with chapters. Look under the hood you'll still see forensic map of state transitions, but this not what we want to navigate most of the time. Sometimes we need to rewrite an early chapter to make the latest chapter make more sense.
the fact that almost by definition stuff that jj does is possible in git makes it hard for some folks to let go of the baggage that git has; it's simply hard to imagine a world where you can't git add ('how do you commit what you need committed and not commit the rest?') or not having to resolve conflicts immediately ('why would I want not to?')
...and it turns out when you answer these questions differently ('working tree is a commit', 'conflicts can committed) but still want git compatibility, jj kinda falls out of the design space by necessity.