You know, he may come to regret it. Missing a family Christmas to hang out with his buddies, using a silyl college band gig as an excuse may seem cool or more fun that just the 'usual' family thing. Of course, years later, when perhaps family members are no longer alive, and these so-called friends of just a few months are scattered to the winds, he might realize that he chose poorly, choosing a few nights of boozing and doing nothign over loved ones. But its the sort of lesson you have to learn through experience, and college is a great tool to help you learn by giving you so many chances to screw up.
@wjp: xmas with the fam isn't the same for all families, for all we know it could be lucky that he finally has an excuse to not be there.... It may sound awful but family and loved ones aren't always the same thing.