Yeah, my stats are terrible due to ragequitters. Either I am playing a 4v4 with a new player, and one or two of the others quit, or someone rages because they keep dying. I can definitely say that I have a 75:25 Win to loss ratio when everyone stays, and a 10:90 win ratio when someone leaves.
There are two things that need to happen; people need to listen to their teammates, and stop leaving. I am so angry at games where there will be a noob who just feeds and leaves instead of listening to my "Don't engage them when there are two of them, and don't engage the (insert name of the good DG on other team)."
People need to listen and ask for help, because I will certainly give it to them, but its frustrating to have so many losses because of stupid crap like people thinking they should leave because they died two or three times.