If it had a better game base and more balancing, it would increase my likings of it quite a lot. The campaign is the better part of the game in my opinion. Online, is frankly just horrible. Servers crash while migrating hosts constantly, you catch boosters in almost every free for all that you see, and no-one enjoys being spawnraped every two or three seconds by a chopper gunner/ac130. And honestly, One Man Army and M203s? I certainly hope that Activision has cleaned up its act by the next game or couple of games. For their sake.
There, there's your valid reason.