CoD is not, "The same game every year". Sure, it has the same mechanics at heart, but the levels, set pieces, and overall content are completely different. Yes, you can accurately say that there is a lack of innovation in the CoD series, but that's because they keep exploring a pretty robust rules set that keeps giving players something fun to play. If exploring the same rules set was never fun, then a FPS shooter would stop being fun after you use a weapon to kill a single enemy. People aren't sick of CoD because of the CoD games, they are sick of the glut of IMITATORS, which choke out new ideas.
CoD continues to be a highly polished if slightly predictable, thoroughly fun game that consistently has a short but stellar single player, some refinement to a very strong multiplayer component, and an offshoot game mode that tries to utilize the rules set already in place in a different way (Such as Spec Ops, Zombies and the like). All together it provides a well rounded, fresh experience. It's no longer the genre-shaking force it was with CoD4, but it is very consistently good. If you disagree, I'm prepared to say that that is your taste, not an objective measure that an be generalized to any larger population.