I think it would be nice to get like a 5xp bonus at the end of the match for every team mate that quit from your team. That way If your team mates both quit you have incentive to keep playing instead of quiting. (I would never quit though )
5XP is not enough I feel, since the win bonus is 10XP so even if you won you would still get the equivelant of 2 team mates quitting.
Ok then like 10xp per person. My point is you dont get any xp for it now, and I'm not exactly sure the perfect xp for it.