"The use of small seminar classes to encourage discussion and promote student engagement with faculty is a critical component of the Core Curriculum, the foundation of Columbia’s undergraduate education.
But as the number of students in Columbia’s undergraduate schools increases, current class sizes and inadequate classrooms have left instructors grappling with how to deliver the ideal Core experience to their students." …
http://columbiaspectator.com/news/2016/10/13/core-seminars-constrained-class-size-space-limitations
It is challenging, I agree, but I never I felt I had trouble speaking up, and even when other people had their hands up, I often found that they had a variation of my point that I hadn’t considered. I think making a few more sections, even if they were taught by graduate students or lecturers, would contribute greatly to the size issue. I have had really good instruction from graduate students and mediocre from faculty; frankly, the biggest factor has always been how many times the person has taught the course before and their enthusiasm.