This is because the sort of high-maintenance git who can only talk about punctuation behind closed doors is the sort of person other people laugh at. It would be hard to get work done with people giggling all the time.
"Being a literary editor requires considerable privacy so that we can discuss copy with some of the very highest level authors in the land. [SPOGG: "The mid-list authors, we don't care so much about..."] Seemingly petty things, like whether something should be a comma or a semicolon, ensures the quality. That simply could not happen in an open-plan office."
Also, "ensures" should be "ensure." Petty things -- such as subject and verb agreement -- ensure quality.