Wolfenstein: The New Order for instance. Or Shadow Warrior. Far Cry 3. Borderlands: The Pre-Sequel! (which is actually coming). Or why the heck not Titanfall?
And if we go beyond first-person shooters, Dark Souls. South Park: The Stick of Truth. Valiant Hearts. Company of Heroes 2. Dishonored. Or even though I'm not into Bethesda's RPGs, Fallout 3 and/or Skyrim would also important games to port. There are tons of games far more interesting than any recent CoD.
See above and tell me once more I'm not into fps.
You make many excellent suggestions above in my opinion but in fairness, Call of Duty is a hugely popular series of FPS games and since many people do like them their personal requests and priorities have as much merit as anyone else's.
If the game in question was something obscure, I could better understand seeing it as a low priority compared to others but that is not the case here.
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Counter Strike would like to have a word with you.
Frankly, I'd also think that porting a two year old Call of Duty game would be a waste of time. If they're going to do CoD, they may as well focus on Advanced Warfare.
I would disagree there as some people really enjoy the single player game in each of these too along with the multiplayer. With their popularity they have enough staying power to still be worthwhile purchases well after release even if they are not the most current iteration.
I just checked Steam stats (5:35 EST US) so not prime time and found the following:
Call of Duty Black Ops II multiplayer has 5,701 players currently and is number thirty on the top 100 list at the moment. (peak 8,853)
Call of Duty Modern Warfare 3 multiplayer has 3,731 players currently (peak 6,328)
Call of Duty Modern Warfare 2 multiplayer has 2,755 players currently (peak 4,408)
Granted, the above numbers are dwarfed by the big hits CS: Global Offensive, TF2, etc. but there's no shortage of people to play with. Interestingly, COD Ghosts came in behind both Black Ops II and MW3 in online players. So much for a newer title having more players. Ghosts had 3,540 (peak 4,110)
Multiplayer aside though, again I wouldn't discount the appeal of the COD single player experience to many as well.