Dont forget, that students go to schools and universities not only to study and gain knowledge only on the subject. There, they get valuable life experience, socialize, gain different skills. School or university are not the places where you only go, listen teachers, go home and make homework. In some point, if students gamble, they can gain such skills as bluffing, tactics, socializing, reading emotions. I dont think these are useless skills to have. Nevertheless, the more students know about the world around them, the better it would be. When graduating, the would be very versatile persons, instead of robots who know only how to learn, and totally lack of any kind of creativity.