I love the Battlefield series but I've never cared for the co-op mode in any shooter. If I am playing a shooter online I want to kill you, not be your friend. That's where all the fun and strategy (well for Battlefield anyway) comes in.
I see you've never played Arma 1 or 2 or any Rainbow Six/Ghost Recon games on PC. We need more console games with co-op, especially co-op campaigns, since it's much more fun to play a campaign with a group of friends than some dumb AI imo.
True I have not but in the games I have played co-op with I simply have not enjoyed the co-op experience. Of course I am referring to 2-player co-op and not squad based (more than 2) which you may be referring to?