Are they legal entities with massive assets that act demonstrably in their own self interest, against the interests of the publicity c, their students, and their skilled workforce?
Are they overseen by a bunch of MBAs executing classic managerial practices and financial manipulations?
I have the same thought when my alumni foundation hits me up for a donation: I already paid you many tens of thousands of dollars more than my education actually cost you, so why should I give you more? Aren't you already the worldwide #1 recipient of my "charitable donations"? I imagine many of my generation feel similarly, and wonder if it is making an impact on alumni donations in aggregate. I can imagine being a lot freer with my checkbook during those calls if I had been able to pay for my whole education with a summer job like a boomer.
I have a history degree. It is pretty cheap to hire history professors, but they still didn't do it and mostly I was taught by adjuncts and grad students. My education used no expensive facilities other than the library.
Also it's a public institution, so if we want it to do research we should pay for that out of tax revenue instead of making 18 year olds take out a mortgage's worth of undischargable loans, and then calling them in ten years in hopes that they want to hand over some more for no benefit.
Ask yourself if you feel comfortable giving a billionaire some of your hard-earned money.