"None of this has anything to do with your ability to perform the desired task" is the major flaw in this. Social interaction is a pretty huge part of any job where you work with people, and so-called "chemistry matches" are often rated as the top thing teams are looking for. This is why so many hiring managers will bring in other team members into interviews.

Edit: just because you don't like this fact doesn't make it less true. People want to work with other people that they don't want to strangle.