Martin's response is great; I'm definitely saving this one for later.
I'm actually starting up a game of my own, and one of the characters (the group's decker) has Charisma 1 and no Social skills. The player's take on the character is that he's that kind of savant-like tech genius who's just no good at talking to people, so I let it go, since that's the kind of character he wants to play.
Though just because his character is socially inept doesn't mean he isn't aware of the fact; I've known plenty of people who know, empirically, that they're just not very sociable, and so they let friends, family, significant others who are do the talking for them. Though they are more prone to losing their composure, so I might impose composure tests on him in stressful social situations to reflect that fact.
