I have seen questions in the past about why one school sells alcohol at their games and one does not. It's up to the school. Here is what the NCAA says:

Alcohol Advertising
The NCAA is concerned about alcohol abuse linked to athletics events. As a result, the Association strictly limits alcohol advertising during championship events and works to educate student-athletes and fans about the abuses of alcohol.

As with all NCAA policy, this is one determined not by the NCAA national office staff but by leadership from the membership. The NCAA provides its members with resources to assist in educating student-athletes and creating and maintaining an environment that promotes healthy choices about alcohol.

Championship Policy -

•The NCAA has for years banned sales and venue advertising of all alcohol at its 88 championships. Host sites are required to cover up any ads for alcoholic drinks.
•The NCAA does not control the regular season in any sport, nor does it run the postseason for the Division I Football Bowl Subdivision. Individual schools and conferences oversee the regular season, including game operations, broadcasting and advertising. The postseason for Division I Football Bowl Subdivision is controlled by the Bowl Championship Series and individual bowl committees.
Advertising Policy -

•The NCAA limits alcohol advertising during telecasts of its championships to no more than 60 seconds per hour during a broadcast, and it prohibits ads for all beverages where the alcoholic content exceeds six percent. Many of the alcohol ads contain language stressing the legal and responsible use of alcohol.
•Pregame and postgame telecasts are not under NCAA control and not subject to NCAA policy.
•In August 2008, the NCAA Executive Committee affirmed the Association's alcohol policy, including for advertising, describing it as very conservative and appropriate. Moreover, there have not been any proposals from the NCAA membership to change the Association's alcohol advertising policy.