I never liked Call of Duty, mainly because I felt I was no good at first person shooters, reason being is that I personally preferred the slow calculated approach and working as a team which Left 4 Dead certainly promoted whereas games like Call of Duty, there was nothing but an influx of lone wolves. In playing Black Ops 2 at times I was like "alright guys you've shown you're awesome by getting a 31-3 kill death ratio now can you please help us capture some flags, pick up tags, set the bomb whatever or however it is you actually win the game?"
Don't get it misconstrued as I am not one of those people that say “I only play the objective which makes me better than you even though my KDR is 13-29, it's your fault we lost” because I personally believe that a good team needs a mixture of people playing the objective and people that are slayers.