IMO, as quik mentioned, a lot of athletes see it as their one "release" for the week. College can be quite stressful at times, esp with track and a full load of courses. Sometimes a negative (staying up late and drinking) can be a positive for some even though it is detrimental for a variety of reasons.
I think it is more of a problem when athletes are drinking mid-week especially when the pedal is to the metal when training. Most don't properly hydrate nor get adequate rest and the work-outs suffer along with raising the risk of injury.
As far as combating it, I have talked, warned, and even threatened my athletes about excessive drinking. Ultimately the athlete needs to choose which path they want to take as far as the level of success they want to achieve.
I probably just reiterated a whole boatload of points already made . . . but those are my two cents. 🙂