The easy answer is to say that students are so busy that they don't think they have time to seek help that doesn't satisfy an assignment. I'm not sure that that's the whole answer. I suspect many are embarrassed to ask for help.
Have ever asked students why they haven't sought help or why they waited until it was too late?
Is it possible to drive students through the support service site to get information they need to complete an assignment? This might be enough to get them the comfortable with returning to for help.
