Dear Criterion, Dice, EA, Valve, Infinity Ward, and most other game developers.
Like most other gamers, I grew up on systems like the Nintendo and Super Nintendo. As these systems didn't have the fancy pants online capabilities that the newer consoles have, our only source of multiplayer was having 2 controllers and playing games with the people sitting right next to us on the couch.
For me, this was always with my brothers, and I remember the fun I used to have when all three of us would sit infront of the TV passing the controller around everytime somebody won a race or lost a fight. Everything about it, from the taunting and cheering, to the "OMFG did you just see that?!" moments were all so memorable because we were all sharing the experience together, and it's something that we can still enjoy to this day.
Now why would you want to take that away from us?
I don't know why you're taking splitscreen out of the games you're making, maybe its a cost thing, maybe you want the game to run at its full capacity by only ever using a single screen, or maybe you're mistakenly thinking that people don't care about splitscreen anymore since the introduction of Xbox live. Well, in any case, you're wrong.
Sure, games like Cod4, Bad Company and TF2 don't really work in a one on one local splitscreen scenario, I'll admit that, but Epic and Bungie have had the good sense to realize that maybe 2 people might want to play online without using 2 Xboxes and 2 Tvs. By having splitscreen as an option when playing online multiplayer, you give us the chance to make the experience physically social again (and I don't mean social in terms of the people you're playing against online). I'm talking about actually being able to invite your friends around so 2 or 3 or 4 of you can play together against other people on Live. Now if Halo 3 and Gears of War can do this, why can't you? You've been coding splitscreen into your games for years, so you obviously know how to do it, so why the hell are you stopping now?
Now the second part of my complaint/rant/whatever, is that not only are you choosing to not use splitscreen when it could be very usefull and appreciated in conjunction with online play, but you seem to be phasing it out all together in your newer games. In regards to shooters, this doesn't really matter, but why the fuck wouldn't you allow local splitscreen play in a game like Burnout Paradise?? If there are any kind of games that've always worked in a splitscreen format, its Racing games, yet you decide that the best option is to build an amazing multiplayer experience, and then limit it to only people who play online (and we all know how pleasant the average Xbox live user can be right?).
So. You want to provide the best multiplayer experience for your customers? Well how about you stop building more maps for the time being and start working on how to implement splitscreen in your games. Left 4 Dead seems to have the right idea, so follow suit, let people share the Console when playing together so that they can start sharing their gaming experiences like we used to again damn it!