OK, I'll bite. I am a sometime programmer, mostly a data analyst. I acquired Emacs less than two years ago, mostly because it could highlight both LaTeX and R code for me, and allowed the evaluation of R code in an attached buffer.

It was awful, I tried it twice before I actually succeeded in switching to it. But eventually, I got used to all the arcane keyboard shortcuts, began to appreciate the power of a program that allowed me to interact with everything (well, except for ncurses based terminal applications) and I became hooked.

I firmly credit Emacs for making it easier for me to switch to new languages, I've learned more about GNU tools from info than from anywhere else, and I absolutely adore keyboard macros (as they always felt like something a program should be able to do). So, for me at least, the benefit of learning this arcane program was that it exposed me to a method for learning new things while still having some level of skill in the environment.

That being said, I really need to learn some vim, for the logging into a remote server with no permissions scenario.

He basically said he uses a text editor for X subset of text editor features and can't see why Y set (where Y > X) would be of any more use to any one. That's classic Blub. Until you learn them and use them you can't really "envision" why they are any more useful than your current workflow.

I can envision all kinds of useful tools an editor might offer; I've implemented a few of them. What I can't imagine is how any number of fancy editor features would ever add up to significantly higher productivity, given that every programmer I have ever met spends an order of magnitude more time reading, thinking, and discussing than actually editing code.

I don't disagree with that last sentence, but even acknowledging that, getting a whole lot more editing done in a whole lot less time, using significantly less keystrokes, makes for a much more enjoyable (and almost by extension: more productive) working experience. Not many things in programming are as soul-sucking as repeatedly having to bash the same keys or mousing and clicking around to translate your thoughts into working code. I think you are really underestimating the usefulness of some of the things you can only do with command-mode editors such as vim, if you think their only merit is saving a few seconds of typing.

It's not about saving time per se, it's about saving context switches and wasted brain cycles.