Yes I know but you always have to set it up.
I am talking about ingame communication that is implemented by the developers.
Skype, teamspeak etc is great when you have a clan etc... But not always a person gets into a game with a clan. And not all the servers have teamspeak channels etc...
Today I was playing BLOPS2 and I heard someone speaking, than I spoke back it was nice. We had a good conversation and helped each other. There was no need to setup anything. Kudos for that to Treyarch.