Put it in the perspective of a football match. You have a star striker who is bringing in fans in the thousands, and winning you every match. Why the hell would you want to then share that guy with your closest rival, thus halving your fan income and destroying your match advantage?

Personally, if you dont get it you're only really missing out on the Broadcast map. The others, Creek especially, are fairly average. Actually, I take it back, I hate Creek. If you're anything but a Sniper you're going to get ahnilated by the four or five people sat on top of the cliff. If one team owns it, that team would win.

Wait for Modern Warfare 2, unless you're really desperate.