"It's not like they offered up the naming rights to an auditorium for corporate bidding."

Isn't that exactly what they did? "Give us $30M and we'll name a building after you". The only difference is that when you donate enough to build a building, you get your name on it in perpetuity, not just a fixed term. Oracle reportedly paid $20M - $30M over 10 years for naming rights to the Oakland Coliseum.

Not that there's anything wrong with it as naming academic buildings after donors has a long history.