To be honest with you, I think that there is something wrong with professors when the average test grade is in the 30s, especially when students attend class, and work so hard outside of class.
Either the professor is a bad teacher, doesn’t know how to construct an exam around the material taught or, more likely is on some power trip aimed at “breaking” even the hardest working, best performing students.
Why not focus on teaching the material and confirming that the students learned it?