I don't know why there isn't an option for all. I enjoyed MW2, for a while, I got another game and moved on, now I'm embarrassed to get on it, I decided to give it a try about a week ago. For the first two games, I did alright, and the best part, only one person had a mic.
Then I got switched to a new game, fine, whatever. Then, right as I spawned for the 2nd time, I got instantly Noob Tubed. This continued on until the end of the match when I was furious. This brings me to my two personal worst points of MW2. Noob Tubes and 5-year-olds with mics. As soon as the match ended, a very noisy child that had been Noob Tubing me the entire match began screaming "YES YES F**K YOUR MOM N****R F**K YOUR MOM" and followed this statement up with what sounded like someone reading off the entire list of swear words read by the worlds most annoying child.
I could rant on and on about what kind of a household that a young child would have to be in to be able to yell things like this, but I digress. I thought about how low some scores would drop if MW2 dropped Noob Tubes and all points earned with Noob Tubes.
Most of these options on the poll are correct for reasons why I don't play MW2 anymore. The single player is great, I loved that. But the multiplayer needs some serious work before it reaches what both I, and a lot of other people want MW2 to be, a tactical war simulation that takes actual SKILL to be good at.