Because so MANY MANY MANY developers don't know when to implement and where, I dislike a world where bullets can shoot through most materials, because this is a game, and I am not supposed to be a fucking tactical expert, but then there are times where a walk off a building does 60 damage out of a total 100, when I jump down the stairs on a regular basis and the most that happens to me is....well fuck all, a drop from that height don't hurt a bit, but then I want to approach from the water but I need a gun that doesn't fall the fuck apart when it gets hit by a sprinkler in the yard, and then we get things like a knife kills me instantly, but a fucking shotgun to the chest and they are still moving, or a fictional shooter where the big aliens can take SLUGS to the fucking face and not move, but I take one to the ankle and I need some fucking Calpol, the rules MUST be within some coherence or the game falls apart, and a lot of the time reality isn't really playable unless you tweak a lot of it, so they just sprinkle realistic every now and again.....but on a more personal level I'd have to say that human designs of weapons are always so very human, a fictional, fantasy one has more variety as a game to implement something without a previous measure, sure you may have played games about shooting guys in the head, but what about shooting guys in their top left shoulder where their heart is located with my boomerang saw blade shooter.....yeah welcome to a whole new game friends.