Legitimate game thrower are very prominent in turf war, if not entirely there and rarely in ranks.
In ranks, you're more likely to find braindead kids that give up because they don't have the mental capacity to keep playing when they are possibly losing.(I'm just a bit salty from those players, I don't believe they deserve their rank if they can't be bothered just because the ennemy is pushing well.)
While reporting them is good, nothing will happen until that player has received multiples reports. So I can't stress this enough; if you encounter players who are unsportmanship(Stop playing for XY reasons, camps, squidbags, etc.) please do report them, don't be an ally to that attitude.