Rant Mode [ON] OFF
It all comes down to one thing, "My console has the advantage over yours because that game is on another platform so it does not benefit your console."
Ps3 fans have to discredit games such as L4D2, Mass Effect 2 etc. because they do not want to make it seem like those games are a strong-point for the 360, which they actually are. I agree that you definately can't call a game on PC and 360 an "exclusive", but you can however call it a "console exclusive" because of the fact that it is on ONE console and a Personal Computer. The fact remains that a person going out to buy either a Ps3 OR a 360 is not going to end up walking out with a PC.
A simple sulotion to this problem is to simply say "Microsoft Exclusive" because you can only play them on MS platforms (Windows PC/360) and if you can run Mass Effect 2 on Linux or a Mac then you deserve some type of reward for a technological breakthrough. I also find it funny how every single Ps3 owner also owns a super high-end rigged out gaming PC as well... Better yet just say "360 games not on PS3". Problem solved.
As to why I would buy these games for 360 instead of PC. I ENJOY playing on my 360 more than I do an my PC. I am not going to claim I have this monster PC but I can jam the latest games no problem. 360 is just more enjoyable for me personally. As for PC having better graphics, true, however not everyone can max out settings on their PC and still have the rock solid framerate.
In the end it is not exclusive, but it does benefit the 360 more than the PC and certianly more than the Ps3. Just look at how PC/360 games sell on 360 as opposed to how they sell on PC, that says it all right there. In reality, according to hard numbers, if you choose to play these games on PC instead of 360 you are in the minority. However I still support PC gaming to the end.
Rant mode ON [OFF]
I am not going to argue with you. It will simply be a waste of my time, and yours.