Not confused.
Actually UCLA (44,947 Wikipedia) has a larger Student Body than Pitt (28,617 Wikipedia) which produce a significantly larger pool of alums who can attend football games.
UCLA had a football home attendance average of 67,000 (2016) fans while Pitt had a home attendance average of 48,000 (2016). UCLA produces 1.57 alums for every 1 Pitt alum.
If Pitt were as large as UCLA I would expect Pitt to average about 1.57 times 48,000 or 75,360 fans (similar to UCLA but Pitt is smaller.
I think Pitt needs to tarp (Right Size) Heinz Field down to 55,000 fans (Old Pitt Stadium seating) when not playing Notre Dame, Penn State West Virginia.
Penn State on the other had has a student body of almost 90,000 students so their alums ratio would be about 3 PSU alums for every 1 Pitt alum. The fact that Penn State can get 95,000 plus alums/fans to attend football games is not unexpected.
HAIL TO PITT!!!!