We will use them to let you know where your MS is in our process. We'll bounce your book without looking at the story. We see a lot of manuscripts. Lots of manuscripts. Lots and lots.
Life is short, and our print schedule is crowded.
OK, here's the real truth. Everyone knows that Editors spring from a ray that ennobles the universe and informs it with all that is good. They are creatures of truly fine sensibility who would never be so cruel as to reject your obviously superior MS on the basis of a single mechanical error. Your MS is first seen by Clerks, the antithesis of all Editing. Clerks are barely humanoid life-forms drawn from the cooling pools of leaky nuclear reactors.