In all honesty making a minimum time would probably result in the same behavior (waiting x minutes before resigning the game). Even if you were to somehow find a way that insured that the other player had to actually play out a whole game, they could always play poorly intentionally. The only real option if you don't want to play against players who do this, or who are sandbagging, is to take note of who they are when they do it and no longer play that user. But like tonystark said, "points dont really matter as they have no definite meaning."
In answer to Barbro: People sometimes give up their points because they wish to appear to be weaker than they actually are, usually to convince weaker players to give them games; or for deceptive purposes for whatever reason.
