That's what I've learned from MW3 and now Black Ops 2. The previous games felt a little more strategic and like you had more control over your situation, but the newer games are trending towards this "slot machine" type addictiveness.
What I mean is that in a slot machine you have a very low chance on each attempt to get a big prize. In every match of call of duty, you have a very low chance of getting a big scorestreak or a big k/d ratio. The game is fully designed to be near-impossible to survive. Between the maps being designed to allow people to sneak up behind you, the completely and totally random netcode never knowing where the game is going to register your position or if it'll even care that you pulled the trigger on someone, and the scorestreaks killing you without any chance at reaction or defense.
Pulling the lever and getting Bar, 7 , Cherry is just like spawning and a hunter killer drone drops on you 3 seconds later. You had no chance. There was no skill involved. The same way when the game starts choosing to pick your shot over the other guy's shot to be the winner and kill someone and you start getting scorestreaks and send a helicopter over the map mowing the entire other team down. You just hit 7,7,7, and there still wasn't any skill involved, and it was the other guys who had no chance.
I think that with the unstable nature of internet connections and latency it was decided at some time that it was just simply better to inject a huge dose of random chance into the game because they have no way of knowing what's actually going on at each player's local machine most of the time in a match anyway. So the addictive nature of gambling and adding the random chance of success replaces what used to be the addictive nature of leveling up your character and getting new items. People will keep hitting those reels or going for another hand of cards because of the chance of getting a win. Call of Duty works the same way, and is so popular and addictive because of it.
Anyone else feel the same way? Maybe blackjack is the better comparison - there is an element of strategy, but it's not the deciding factor on if you win or lose. I feel like this was never the case in CoD4, WaW, and even MW2. The maps were designed to allow people to spawn and then enter the map. Since then the games have made maps smaller and smaller, and spawns closer and closer, all while adding more and more unstoppable overhead killstreaks that can see everything and kill people instantly.