A lot of the time, a university will raise money for the stadium via private money and revenue bonds. So none of your tuition goes to funding the stadium, although the university likely doesn't profit.

Real estate and businesses have a vibrant financial market, so you don't necessarily need large figures to participate. You're not going to raise $100 million in revenue bonds for a professor to study sea slugs, because there isn't any revenue.

University administrators do not have the power to make investors fund sea slugs over stadiums. If you can convince the nation's pension funds, hedge funds, and private investors to somehow buy science bonds rather than revenue bonds, then the administrators would stop buying stadiums and start hiring sea slug researchers.

I would tend to agree that the money might be better spent on building up dormitory or apartment housing for students rather than stadiums, if the revenue and costs were equal. But I'd need to look at the financials.