Whats so special about CODMW2 or COD:BO?....I just don't understand, can you explain it to me?

Ok, Battlefield 3 have all kinds of Vehicles you can drive, Helicopters and Jets you can fly, the best destructible environment system ever created in any games, 64 people multilayer with Dedicated Servers. Now tell me what does CODMW2 or COD:BO have that is so fun?.....I played them both online and single player, and I got bored in couple of days, now tell me whats so special about COD Series?...there is nothing new, no Vehicles, no Choppers, and no Airplanes, what do you find in this crappy games I just don't understand?....all you do is run-and-gun like a Rambo all day long, nothing else to do really.