I find plenty of helpful people who point out chests, pitch in with a tough firefight, and jump into a public event to help out. I try to alert people to chests, though some don't get the "firing the gun" hint or are in a rush to get somewhere else. Even though I play a lot of co-op with my brother, we both tend to be aware of other players. Being careful not to butt in on their gaming, but ready to pitch in if a little help is needed. I will go out of my way to try and revive another player, but they usually respawn before I can get to them. i also try to bow or wave to those who have pitched in during a public event. Having done a few solo or with just one other person, I certainly appreciate the extra help..