The point is it could get nerfed and still be in a really good place. Being in a really good place and being overpowered, meta-dominating, and broken are different things. Rather than buff PLD and DRK and risk upsetting the balance further (it would not take much buffing to PLD to put DRK where PLD is now, and they can't buff DRK without PLD crying even harder, so they would really have to buff both, not one or the other), they should simply bring WAR down a notch. DRK is only used because of how magic focused the raids are, if they were physical, you could easily bring PLD or DRK, but you'd still ALWAYS bring a WAR. They aren't going to bring DRK and PLD up to that level, at least not on DPS, because they (foolishly imo) stated that DPS is part of WAR's utility. LOLOLOLOL WHY NOT JUST SAY "WINNING IS PART OF WAR'S UTILITY"?
So unless they decide to go back on what Yoshi P said, they ain't bringing PLD and DRK up to WAR DPS in both MT and OT slots any time soon. But they could nerf WAR's DPS and mitigation ---slightly--- in order to make them not utterly mandatory for any progression group.
The power and ease with which WAR wields it while maintaining survivability is great and if they actually buff the damage and ease of DPSing while mitigating damage on the other two tanks up to WAR levels, great. I just feel like that's unlikely and a more convoluted solution than to simply take WAR down a peg from "broken and OP" to "a good, well rounded tank that performs in content and has adequate raid utility".
Pretty much, what I believe, is that PLD and DRK are tanks, and WAR is an overpowered obscenity. Rather than make PLD and DRK overpowered obscenities, since they function fine in a vacuum unless they're having to fight for a raid-slot against a WAR, they should just make WAR a tank. =P
Go try and make a raid group with a PLD/DRK composition, I dare you. Unless they're all REALLY good friends, they're gonna laugh in your face.