Some of us got "plays well with others" on our report cards as kids. And some of us definitely did not. Co-op has been a staple & centerpiece for gaming since the introduction of the Home Console systems & as the era of Arcade gaming saw its retirement. But, as technology & gaming both mature, it seems as if even co-op gaming is getting ready to head to a nursing home, as developers, and maybe even some gamers care about it less and less.