> You are exactly correct. As to why it’s unpopular, I believe it’s just that no one has given it a fair try. Once you have done it for at least 20 hours a week for a few weeks you will understand that typing is not and has never been the bottleneck in programming. If you have not tried it then you cannot have an opinion.
I haven't tried pair programming except in very ad-hoc situations, but doing it all the time sounds utterly exhausting. You're taking programming, then layering on top of it a level of constant social interaction over it, and removing the autonomy to just zone out a bit when you need to (to manage stress).
Basically, it sounds like turning programming into an all-day meeting.
So I think it's probably unpopular because most software engineers don't have the personalty to enjoy or even tolerate that environment.