Ghosts had the luxury of coming after Black Ops 2, arguably the best game in the series.
AW came after the worst game in the series since COD4. I think true decline can be identified if Treyarch can't bring back all the people disenfranchised by Ghosts with next year's game.
Plus, I have a sense that COD eSports is really going to make a significant push this year, moreso than it did during Black Ops 2.
anything is arguable...but the general consensus was that blops 1 and 2 both sucked.
COD is the same thing every year. people are starting to catch on.