I've talked before about the down side to giving homework: doing all the grading. I think I've talked before about the down side of grading: wherein the grader spends more time making sure all the parts of the assignment were actually done as opposed to giving genuine feedback on the work that is there. A lot of the time that verges into the world of "did or did not follow instructions." When you get to the point where in a college class you are reviewing compliance with the instructions, that's pretty far down the down side.
Of course all of that assumes they've actually managed to turn in the work.
Head --> desk.