If you are a Unix fossil like me then you no doubt have a religious position on the greatest editor of all time. Either your mind is wired the right way and you appreciate the beauty of Vi or you were adopted early on by a band of baboons and prefer the finger gymnastics of Emacs :-).
The Register has an interview with Bill Joy (pretty much the father of modern computing, in my opinion) in which he talks about the history of Vi, where he says:
The people doing Emacs were sitting in labs at MIT with what were essentially fibre-channel links to the host, in contemporary terms. They were working on a PDP-10, which was a huge machine by comparison, with infinitely fast screens.
So they could have funny commands with the screen shimmering and all that, and meanwhile, I’m sitting at home in sort of World War II surplus housing at Berkeley with a modem and a terminal that can just barely get the cursor off the bottom line.
Joy goes on to say “People don’t know that vi was written for a world that doesn’t exist anymore“, which will no doubt serve as ammunition for the Emacs crowd! I think however that what might be an anachronism in one sense might in other important senses be pertinent (and even perhaps remedial) to contemporary needs and ailments.
I don’t have to look far for examples. Vi and Emacs are in typical use editors for programmers. Consider recent developments in text editing. The preference these days runs against complex multi-function tools with a zillion knobs, bells and whistles, to “distraction free” editors and simple styling methods such as Markdown.
Emacs is for lovers of complexity and with the mental (and at times physical) resources to support that complexity. Vi is for the rest of us who manage complexity by compartmentalising actions to aid concentration.