Submitting work (or not)

Lossy's Law (No. 1)

The size of the student's excuse is directly proportional to the size of the submitted work to be handed in.

Why? Why should that be? For example, for programming assignments we get excuses like "I had flu", "Oh I thought the hand-in time was 9pm, not 9am" (really?), "I thought it was due in on Wednesday". On the other hand, for an assignment for five times as much credit, we get pleas to hand in the work later because of reasons like a broken leg, divorce, homelessness and bereavement.

I don't get it. How does the flu virus manage to miss all the students who have a really big assignment submission?