Right, if you have a really good friend who just clicks with you pairing is great. But that isn't how pair programming at companies is done, they put you together with some other member of the team and tell you to do work, you didn't choose each other you just happened to be there and now you have to be mentally intimate with each other.

But you are right that voluntary pair programming can be a good thing, so we shouldn't ban programmers from pairing if they want to. But the discussion is whether it makes sense to force programmers to pair program. I really doubt that for example pairing John Carmack and Linus Torvalds would be productive, and that is the kind of personal pairings you get at work.