For my first degree, my grades would have been a lot higher, if I'd have stayed home and played wow on the weekends, instead of getting stupid wasted. Nerding out is working out great for my second degree, of course my new degree program is kind of nerdy anyway, and I've grown up a little.It's the social aspect man. If you have roommates the last thing you want to do is be known as the kid that nerds out on WoW every weekend.
And for a lot of people it's much harder to keep the grades up while playing WoW.