http://www.slate.com/articles/life/behind_the_scenes/2015/06/copy_editing_pet_peeves_the_worst_style_and_usage_mistakes_according_to.html

Copy editors are a special, strange breed. We tend to hold strong opinions about peculiarities of the written word that the average person may never consider. Our job is to make sure sentences are as clean, concise, and readable as possible, and even one extra or misused word or punctuation mark can distract from the argument. So we sleuth out even minor offenses and take pride in catching them.