The masters are not pleased. There are so many reasons for a student to extend the amount of time spent at college, instead of graduating in four years. Twenty credit hours per semester, though possible, is an extremely heavy workload. That is about what it takes to graduate in four years. If someone wants to get a job, or heaven forbid, a social life, very little time is left.
Sleep becomes a luxury that is hard to afford.
Learning within the four-year plan has a very limited scope. Not enough time to take something for the pure joy of it. I always saw college as a place to let my experience widen. One of the reasons students do not graduate within four years is changing majors. A large majority of students change their major at least once during their college career.