Vim is cool but... crufty. It seems like the point of this project is to be both extensible and simple/comprehensible. For that, there's nothing like starting from scratch.
and yet every single project to reimplement vim "cleanly" has failed. the only successful other implementation out there essentially ported the vim codebase directly to java. i can only conclude that vim has built up a tremendous amount of sheer value along with the cruft that is not easy to reproduce.
He's not trying to reimplement vim. He's doing a new thing. Part of vim's cruft is in its design. An important part of a clean break is a new interface. Obviously, getting traction with other devs will be difficult, exactly like any other tool.
