From a student perspective, the SW corner's top 20 rows were empty because of one reason: some of us students are a little dumb. There were people standing on the ground level and in the aisles for a great deal of the game, while 20 rows just across the way stayed open. People would rather crowd around the SE corner and sacrifice a seat than just look across the student section. There was one game last year where about 10 rows under the SW jumbotron were completely empty (mind you, block seating was in effect, although once the game starts, anyone can take the empty seats), but we had people over on the other side not only standing in the aisles, but in between rows of bleachers. Two rows stood up on the bleachers (as normal), but then there was an entire third row of people standing on the concrete between the two bleachers.