I don't know what you are talking about on that one. It has a rich backstory. It's games actually humanizes and gives reason for both sides to be at war (most war games have a clear one note villian/enemy faction). It is a futuristic space shooter that doesn't jump deep into sci-fi territory (no laser weapons, cyborgs, teleportation or aliens). The biggest thing about its multiplayer is that the classes and Jobs are very distinct. Unlike some games where class/job only equates to weapons being used, in KZ MP there are both distinct active and passive skills that define a class.
To this day, the battles are some of the most chatic I ever had, with snipers not just being hard to see, but completely invisible, scouts that can cloak themselves and literally look like one of your team mates, unmanned Arial and ground turrets, proximity based c4 (omni directional) and freaking spawn grenades. That is just some of the insanity that could go on in a match.
Imo, anyone that states that KZ doesn't has it's own identity, either hasn't played it, or never payed enough attention to contrast and compare with others in its genre.