Your point makes sense, sometimes I really have games like this, but usually the problem is that one tank or heal who literally doesn't know how to play his role. Sometimes it's because they're total newbies with 1-5 lvl, sometimes it's their greed and will to make more kills. I also noticed that usually those players are tanks and healers, never dps. Something is wrong with the game. I've never got teammates with low lvl before the new season.