I wish it was only 10-20%. I'm a non-trad student at a small state school and IMO they try to inflate grades via homework. This semester I aced my exams, but only had time/energy to complete ~60% of my homework. Since it was 30% (on average) of my final grade I ended up with a 3.0 for the semester.

IMO the cost and value of college have long since diverged. Colleges and creditors are colluding and, unfortunately, many borrowers feel they have no choice but to participate in this sick game.