This is what WZ/COD is to me. It has been this way since they went away from WW2 games and went thru Modern WF, Advanced WF, added Zombies, and all the other intergrations.
In a way, WZ is just like modern post-internet society, throwing everything in the pot all at once, for better or worse.
But for those that complain about COD, here's some advice: Kill off what you think COD is supposted to be, and treat it like you are watching this movie, where anything is possible. If you don't like the movie, then go watch/play something else.