Well it is not perfect, but I have had up to eight TVs an only two consoles in a room playing Halo 2 not too long ago. I have not tried it on Halo 3 or Reach, but it would be surprising if it was not there. You are right of course that most games lack split screen, but that is a far cry from saying that shooters are no longer social when the reality is the are more social due to more options in how to play.
That's not more options, that's different options, and it's certainly not more social. Playing online with a headset does not make you social. The internet is not a substitute for real human interaction. Hell, we do a large amount of communication non-verbally as humans, with body language and facial expressions. You cannot substitute that with online play. Hell, I won't even CONSIDER buying a racing game without split screen, because that's literally the only way I'll play it at all.
I think you read my post incorrectly or I did not make myself clear enough. I said it had two xboxes connected to 8 tvs in one room. That is more people playing than the 4 person split screen you are talking about. I also mentioned spit screen coop. I could name numerous titles this gen that do meet that description.
Using the internet for more human interaction has been thought to be a downfall to society, but it is not all bad. Your website is partially run of of interaction on the internet so you can't compleatly say it is all bad.
None of my posts have suggested I prefer talking on the headset anyways to strangers, when in reality the best times for me have been playing coop campaigns with friends of many genres in the same room. Still the genre that has the most coop is the shooter.