Over 4 new Call of Duty games have been released in the last 3 years, what has changed? Absolutely nothing!
There are 2 major issues here, firstly too many COD games are being released and they are being released too soon, Secondly the games are too similar and do not innovate.
In terms of Black Ops 2 it is the only release in a while that i truly did not enjoy, the main reason i think is because i am bored of the same exact thing over and over again, the games look exactly the same and it seems that Treyarch are not making any effort to create something new.
If Call of Duty continues this trend i don't think it will continue to stand for too much longer, They are oversaturating the market with this series and worst of all it is being made by a studio that is only copy and pasting the games without any innovation.