Are you referring to a specific review, or a grand conspiracy theory about all reviewers in the industry who have come up with the insidious plan to unfairly knock Killzone and pump up Halo, CoD, and BF? How clever of them to have all given Naughty Dog's games great reviews to keep us from discovering the plot to undermine Sony's first party games. And it's even more fiendish that they gave Ghosts lower scores that prior entries in the series for exactly the reasons that you're saying they've ignored.
I won't try to defend Ghosts, but in the case of Battlefield, you're wrong. It's in many ways similar to its predecessors in the fact that it's still 64p multiplayer with tanks, jets, heli's, squads, and four classes. But it's by far the most refined form of that type of multiplayer, and with maps (with the exception of one) that actually were designed for 64 players.
You can't look at reviews merely in comparison to their predecessors, but to the genre as a whole. I suspect that a big part of Ghosts' scores were the result of it coming out a week after BF4 and not comparing favorably against its rival. And then KZ4 comes along and many reviewers seem to have played it and thought "hmmm, this is even worse than Ghosts, so I can't score it higher."