You can't ruin what was already ruined.
Actually, I do not mind Call of Duty games. Technically, it is an amazing game. Many guns, upgrades and rewards, online gameplay and thrilling and cinematic singleplayer. Only real problem was balancing.
In reality, the community made it what it is remembered for today, a stuffty game with overused features.
I am not a CoD fanboy, but I am also not one who joins in the group of people that countlessly bash at the game.
Overall, the game was ruined by the community, not the developers.