It was hard to rate him, not because he has both good and bad qualities, but because he rarely appeared in class.

It was hard to rate him, not because he has both good and bad qualities, but because he rarely appeared in class. Throughout the whole semester, he did not take classes regularly. Instead, toward the end of the semester, he took classes that exceeded the scheduled class time. He was punishing us for his own negligence. He is a teacher, yet he does not seem to have time for his students.