Because geeky college kids go to places like Disney, where it isn't one huge pick up scene and if they do meet someone, its likely to be someone more interested in discussing Pixar animation than drinking a 24 pack by themselves.
However, sometimes you don't get a choice in what young adults want to do. My son - he's going to a beach where he will see if he can drink a 24 pack by himself. And as long as none of his young adult stupidity leads to life altering circumstances - its young adult stupidity. I can think back to my own young adulthood and say "I hope my own kids have the sense never do THAT!"