The larger the class, the longer it takes the professor to grade the homework and to hand it back during class, so there is less time spent productively for lecture and discussion. Most students don't like to be crowded together too tightly, packed like sardines in a can. The Fire Marshall says it's a fire hazard to have people sitting on the floor, exceeding the size rating of the room. Students who sit on the floor during an exam tend to not do well. The larger the class the longer students have to wait to see the professor during office hours and the more difficult it is for the professor to get to know the students.
Students find large classes impersonal and less satisfying.
Faculty members often get poorer evaluations when they teach a large class. Large classes may result in the College of Business losing its accreditation. The more students per class the administration thinks faculty can tolerate, the more students they will allow to register per class, leading to a never-ending spiral of increased class size, diminished academic quality and heavier faculty work load. Let them know that they must find funding for more classes and qualified permanent faculty to teach them.