Just finished a short book by Neil Raisman on student retention. His company interviewed 640 students a year after they had left a school to find out why they had left. The study uncovered three major reasons: 1) a feeling the school only looks at them as a source of tuition revenue (30%); 2) dissatisfaction with how they are treated by the staff (yes, this includes faculty) (29%); just unhappy with the feel of the school or the program they are enrolled in (13%).
Of course, one must take the results with a grain of salt, since Raisman's company focuses on improving student retention rates through improving customer service at universities and colleges. Still, given SIUC's problems with student retention, it's certainly something the school should look at.