In the "professional" gaming world, when a player knows he will lose he is expected to quit so as to avoid wasting any more time on a game that has already been decided.
I agree ... but I'm not sure that dear Bara would approve my interpretation of his post.
It's a GAME ... and many people have limited time available to play.
Personally, I very rarely quit* a DG match, but I do not feel resentment against people who leave before the end.
If a game appears to be doomed to be lost, it is the player's privilege, in a free society, especially in a game where the stakes are illusory, to get the hell out of Dodge and go spend his free leisure-time doing something else.
As some posters have suggested on this thread, some reward should be programmed to recompense winners who have been stuck with quitters ... [EDIT > and add, as someone suggests below, a "surrender" feature, allowing people to yield gracefully and at the same time assuring that the winners get a fair bonus to their stats.]
[ * I will only quit a game under 2 conditions : I'm the only non-bot left and I don't feel that I will enjoy playing with only A.I. substitute OR a team8 is much too abusive on the chat or in his gaming behaviour (that has not happened yet -- but it came close, once).
Recently, I was in a custom 3 v 3 and my two team8s deserted me. I asked my 3 human enemies if they wanted me to continue to the bitter end, and when they said "yes", I stuck around even though defeat, with two mediocre bots as allies, was inevitable.]