Multiplayer? please? maybe?

So today I have a little rant. What is the deal with gaming companies these days and cooperative multiplayer? Is everyone afraid to make cooperative multiplayer games that don't end up just being team deathmatch or something? Look at Bioshock. The game sounds amazing. Will I buy it? No. Single player games really don't do it for me any more. Instead of sitting on the couch playing Bioshock by yourself, how much more fun would it be to have your friend playing it along with you instead of ganking your chips while watching? That alone would make things more interesting. The first letdown of this nature that I can remember is Vampire: The Masquerade, which announced the death of it's anticipated coop multiplayer on it's forums not long before release.

So what am I after? There are games that include coop multiplayer out there. Just look at Gears of War. My point is, how many of you actually played through Gears by yourselves, and if you did, was it not more fun hooking up with someone to beat it? Why can't a game be made for coop game play? Think of the possibilities you could have if there were puzzles set up like Resident Evil Zero style. Where for literally an hour let's say, you had to split up to get things done in tandem, while keeping contact on radio. Think of all the times the NPCs have been right there in the story to flip a switch or something for you. That could be you!