Many people tend not to play COD campaigns and instead just play the online mode and only tend to play the campaign if the servers are down and they have nothing else to play. Do you make an effort to play the campaigns? I do for every game. They are not too long and are not hard so I just do it to get used to the feel of the game.
I agree, I like playing the campaigns to get a feel for the game before I play online. However, I also enjoy some of the storylines. My favorite storyline by far was that of the Modern Warfare campaign.
I actually only played through the Ghosts campaign. I started Advanced Warfare but couldn't get into it. I'll probably play the Black Ops 3 campaign and possibly even go back to the Black Ops 2 one and finish it, as well as World at War.
Since I'm a big storyline kind of guy, I do like to play the campaigns. I just think that if someone takes the time to write a story for a game, it should at least be experienced, if not appreciated. Like Liv6 said, the modern warfare campaign is imo the most well-written so far, but the original black-ops was well told as well. I'm a bit behind, so I don't know too much about black-ops 2's story though.