One of the most valuable assets of a college or university is its alumni association. One of the critical metric's that determines the strength of a school's alumni group are the percentage of alumni who give money to a school every year. Alumni wouldn't likely hand over money to a school if they felt no affinity toward the institution. However, I do believe many colleges and universities receive large donations from alumni and others are that these donations are tax deductible.
With all that being said I firmly predict the demise of this revenue stream for one simple reason - "STUDENT DEBT." Loyalty to one's school is a big reason for giving but if one leave's that school with a large student debt that now becomes a monthly payment for the rest of one's life not giving an annual alumni donation (at the least very small amount) is going to go by the wayside.
Why should a student give back or donate to a school or an education system that is extorting (perhaps "usury" is the better term) money from individuals because too many jobs today require a degree (many advanced).