If you believed you were going to win a game, you would be willing to spend 30 minutes there without complaint.
If you ultimately lost that game after 30 minutes, you "wasted" just as much time as you would have if you won it.
The fact that someone is willing to put forth the effort to try and salvage a game you believe is lost doesn't mean they're wasting time, it means you are for even queuing up for one in the first place.
People are getting more and more willing to throw in the towel when they fall even the slightest bit behind, and it's really pathetic. Yes, there are games that are decided early, but no game is surer lost more than the ones where EVEN A FEW members of the team have resigned to failure.
Heaven forbid you might need to actually put in some effort and outplay an enemy with the advantage. That might actually require skill...