Deaths are not the problem, let's get this straight, it isn't the deaths part of the k:d ratio that causes stat whoring, it's the kills part.
Kills in arena based shooters like Call of Duty, Unreal, Halo, CS and so on, they are the measure of a battle, the goal is to kill the other side and therefore kills are the "goal".
In a game like Planetside, kills are not the goal. Objectives are the goal. That however does not mean that we should also remove the deaths portion of the equation. Not dying is something that we should definitely be promoting. I don't want people kamikaze running into impossible situations hoping to drop 1 enemy at a time with each attempt, it's just stupid and it's nowhere near as fun as the tactical, strategic combat you get from a group that is actively trying to preserve their lives as much as take the objective.
So, in regards to that there's an obvious solution to this problem. We replace the "goal" part of the equation to suit Planetside, an objective game.
Score : Deaths should be the new ratio. Make kills a very low importance metric, deep within stats pages where it's less in the player's face, place SCORE
EATH larger, bolder and of the most eye catching prominence to the player.
You can positively reinforce this by showing the player their score:death in game when they take an objective as part of an assault, show their score:death increase with a pop up much like the xp pop ups. Provided this score is only considered over let's say a 50-100 hour history of the player's in game play time then it can be a strong metric for how well the player can earn score for their side while preserving their life.
All support and objective based points should earn SIGNIFICANTLY more score than kills. Not just a little bit more, a LOT more, to reinforce that kills aren't the important thing.
In battlefield kills had SOME importance and thus the score earned for kills in BF3 wasn't too much less than other things you do, because of tickets. Planetside does not have tickets, therefore kills are of significantly less importance and the score kills earn as a result should reflect this.
TL;DR:
Score : Death - The new metric that should be psychologically reinforced into players in a number of ways, to promote the activity and type of play that would be best for the game. Players make a game, manipulate them into playing it how it should be played through as many methods as possible, make kills worth very little score as they're really not the objective whatsoever.