I don't find it, or pretty much any other shooter addicting these days. They're all essentially the exact same game with almost no actual improvements, and only marginally different from their predeccessors. Unoriginal and uncreative, in other words.
It's my job to help the next generation, and set a good example for them. And for that I'll gladly lay down my life.
Take CoD 2 for example:
Awesome things in game:
Weapons (E.G Lee-enfield, Bren gun, Sten gun and the Webley are the English ones, not forgetting the German ones, the Russian ones and the American ones.)
Storyboard
Multiplayer
And Graphics.
See what I mean?
Now on to CoD 5: World at War...
The nazi zombies on WaW has been a huge success. It has amazing add-ones, like the Random weapon box and the Bowie knife.
Might be why...
Two fails don't make a win... and three fails don't either. So no thinking about it kiddies xD
I personally don't maintain addiction to Call of Duty, but my theory is that there are two groups of COD players: the actual fans, and the followers.
The fans are sincerely addicted to the real, gritty, FPS gameplay, as well as the competition. Nothing more to say.
The followers are guided by reviews, advertisement on massive scales, and the anti-stigma of COD being the socially acceptable thing to do, the "cool" video game to play and discuss. In essence, they mimic the fans.