I was thinking the same thing, since much of this is now about ego, and we know these Harvard and Standford grads have as big egos as anyone else. It's not up to the alumni, though. I had a conversation about this with another poster on here who is a Harvard and Stanford alumnus, and he pointed out it's more about the administration and faculty than alumni.
The administrations of the Ivies will never get back into scholarship sports, they don't see it as core to their mission. So there goes Harvard, Yale and Princeton. As far as Stanford or Northwestern go, they will never reduce admissions standards to the point where their football teams can put together 85 blue chippers. Maybe they can do somethign in basketball like Duke did. But not football.
Notre Dame has a shot to collect enough elite footballers who also are (relatively) good students, given their Catholic school feeding system. Most of the other top schools won't play.