When I was at the university and started programming on UNIX, the professor said we should try both emacs and vi and see which we like better, and provided links to some tutorials.

I tried them both and liked vi. Emacs seemed slower. In my undergraduate wisdom, I deemed emacs to be "stupid" and went on with my life using vi.

After I had been programming professionally for about ten years, I decided that my harsh judgement as an undergraduate was often incorrect. (I had also deemed Voltaire, Spanish, sociology, microeconomics and many other things as "stupid", and came to understand as an adult that they weren't.) So, I decided to give emacs another chance.

My conclusion was this: vi is better for touch typists. Your fingers are almost always on the home row. Emacs wants you to hit the meta/alt key a lot, which is difficult for a touch typist. It's much harder than hitting shift. Vi makes you hit escape, but that only happens when you switch modes and it's not that hard to hit.

I noticed that lots of skilled and professional engineers never learned to touch type. That discovery itself was odd to me: why would a professional programmer not want to invest the time to learn to type properly: typing fast boosts your productivity significantly. But they do. And my conclusion was that emacs was for them, because hitting the control/alt key isn't as much of a penalty when you're a hunt-and-peck typist.