I'm sorry but your arguments just have so many flaws.
First of all you say:
"While you aim and fire your weapon accordingly, you still don't have control over what you're doing. The game decides whether or not you're going to get the kill, regardless of which player dishes out more damage."
So what you are saying with this is, you have absolutely no control if you over if you get the kill or not. Here is how shooting games work: you aim towards the enemy, and shoot, if it is on target, damage is dealt. It is not a random chance if you will deal damage or not. Therefore, you have control over the game. If you aim well, you get the kill. If you don't, then obviously you won't.
Also, the game doesn't choose a "favourite player" to get the kill, think about it that is just ridiculous.
Oh, and just a little tip. You know on the enemies killcam, where some of your bullets miss, that you thought hit... well that's called the guns recoil... and the killcam is in slow motion, at full speed you might not notice the bullets that miss because of the rate of fire.
You then go on to say:
"Your actions don't influence the outcome of the game." and "You can be a "good player" in Call of Duty, and still receive a crushing defeat."
You do realise, that even though you are good at something, you can still have a bad game. It is the same for every game, or sport etc. Everyone have a bad game...
What I am trying to say here is that Call of Duty is obviously a game, and I don't know how you could think otherwise.
Also, even though you do not say it is a game, you repeatedly refer to it as a game in your post -_-