because there totally isn't new weapon levels, a new killstreak system with new killstreaks, new equipment, new gamemodes, or any new gameplay mechanic at all.
weapons: same boring, generic guns from past games, give or take a few
killstreaks: see above, plus or minus a plane or something
equipment: hardly any game-altering stuff, and it would have been in previous games, too ( smoke grenade, tactical insertion)
gamemodes: again, more generic "new" stuff that will involve planting a bomb or something
gameplay mechanic: i have yet to see a new gameplay mechanic since call of duty 4