In my last interview i learned that the main reason for high school teens and the number of low grades is because they do not see how their grades are more important than the the other activities that they are in. Some students stay that the work gets too hard and when they try to succeed and fail; they see no point in to keep trying. Also, everything that they are in seems to much and they just stop doing the rest of the work.
They next interview i will do is a teacher and a parent to see what they see is the real reason for so much of their work not being done.