Rob Pike created acme because he wanted an interface that would use the mouse, unlike the regular vim setup.

http://plan9.bell-labs.com/sys/doc/acme.html

Meanwhile, traditional UNIX users all developed subconscious phobias of their mice, because they use focus-follows-mouse and therefore moving their mouse caused them to accidentally type in the wrong window. This is why they like to so rabidly claim to be super-efficient typing wizards by using keyboard chords for all their text selection needs.

Acme is also more UNIX-like (Plan9-like?) than EMACS, which is just an alien Lisp image invading your machine and seeking to become an email reader/rampant AI/planet conqueror. I always assumed Hurd failed as a project because, once it ran Emacs, nobody ever really needed to develop the rest of the OS.