Sniper Team 4 said:
Forget--or not even understand--the concept behind "cooperation." You work as a team, not try to hinder and outdo the other person on the same side as you.
Abandoning the game, but not quitting it is another thing that bothers me. This happens a lot in Nazi zombies and a little in Left 4 Dead. How many times I've started a round, just to see another player stand there for ten minutes, constantly dying and screwing the rest of us up. A team can't function if you say you're ready, but you really aren't.
Oh God, this story happened in Killing Floor and it pissed me off:
So, we go on the map Icebreaker, which is known for being a hard and dark map. Six of us, but one person is AFK and it's impossible to kick him. So we spend the next hour fighting six peoples worth of specimens, while our AFK guy was getting torn apart literally seconds after a round would begin.
We come to the last round, the Patriarch (sort of boss battle). Suddenly, Mr. AFK isn't AFK and joins us at the trader. He then outright demands money.
This stupid moron had spent literally the entire game up until the last minute doing nothing but dying and leaving us with more to fight, and now he's demanding we forgive him and fork over our hard-earned dosh.
We ridiculed him for that, gave him no dosh and went to fight the Patriarch. We won, but of course Mr. Formerly AFK was killed before we defeated the Patriarch.
He ragequitted, hilariously. And he wasn't even that good, I was rocking the place as Level 4 Demolitions and we had a Level 5 Firebug, but that guy was a Level 1 Sharpshooter.