Communication problems don't require "bad people", though. Sometimes you have good people who just don't work well together, or who could be assets to the company but aren't communicating well. These things become common at scale. I actually find "performance" rhetoric to be insulting and imbecilic, so I think it's better to discuss impact... but if you have 100 good people, at least a couple are going to fall below an acceptable level of impact, even if they're capable people working hard and in good faith.

This is one of the problems with typical HR mediation practices. In most companies, HR is worthless. That comes from the implicit assumption that one party or the other is "bad people" and that they have to assign fault: if an employee gets a bad review, for example, they have to conclude either (a) that the manager gave an unfair review, making him look bad at this job, or (b) that the employee actually sucks. There's no alternative. This rarely works well, because unless there is a legal reason (e.g. a sexual harassment complication) that impels them to side with the employee, they'll side with the manager every time.

This is one of the biggest problems with performance reviews. They force the manager to take a definitive stance on each employee, and because to disagree with a review is openly to call that manager incompetent, people are afraid to do so even when, by rights, they should.

I get the strong impression from Valve's handbook that being a good person is defined as working well together. The idea that social incompetence is okay as long as a person can do good work may actually be harmful to company productivity, in their view. Of course, this could just be a conspiracy to put all the Aspergers out of work.