I guess it can vary on different peoples playing style in DMs.
Some like to camp back and get easy kills with the locking on of auto-aim.
Others like to run and gun and see who they can kill.
Also players who have bad situational awareness get picked off easily.
I think the main problem is AA and fighting NPCs warps peoples brains.
In story mode or when fighting NPCs online, its easy to just run out and lock and drop everything. You get the feeling of being AWESOME.
Then you go out play AA death matches... And the other players are not giving that player easy lock and drop targets. So their current way of playing like rambo with AA just comes back to bite them.
The most patient player, who moves the least with the best view and cover of the battle field will have the advantage over everyone whos moving around constantly looking for targets.