The idea that real estate speculation being the baseline goal of universities is funny but doubtful.
Instead, consider that survival is almost always one of the main goals of any larger organization. That happens for a variety of personal, individual reasons: job security, reputation halos, personal networks, etc. But in the end, it translates into organizations taking actions simply to survive. And since one of the best ways to survive is to grow, taking actions to grow.
This is true for everything from charities that take care of the poor and sick to for-profit corporations to government agencies. And, of course, universities.
So why does a university spend a ton of money on renovating their football stadium? Simple, it makes alums happier (more donations), it looks better on televised games (enhanced reputation), etc. It helps the university survive.