I think that is because there are many metrics that need to be satisfied and we have some covered but not all. Some of these programs were grandfathered in and that is a metric as well.
After nearly 2000 pages we all know them:
Attendance
Market Size
Geographic location (proximity to rivals or other league members)
Academics
Student body size/Alumni base
Tradition
Facilitates (including OCS)
Notice I didn't add on the field performance which would be why Boise was never asked and Rutgers was. Boise had the performance but few, if any, of the others. So I guess we agree.
We are also hindered by the directional school stigma. It could possibly be a deal breaker for some leagues.
To those who say that we have better attendance that a few grandfathered bottom feeders, I would say that is meaningless.