Back in my Unix days I chose vi over emacs. Vi opened a file almost instantly, while emacs took such a long time that I had a tendency to leave the file open in a window. This was early days in multi-window environments, so I would forget I had the file open in emacs, open it again in another window, and, well. I stuck with vi. This also had the advantage of being the command set for playing Nethack (in which I ascended many times).