A warrior, who is not tanking, has to use berserk to boost his damage. This makes their defence crap and only the defence they have is their high HP and foresight/featherfoot. This is means WAR has to avoid getting hate and AoEs just the same as any other DD. The problem is, WAR doesn't have hate reduction abilities. In the contrary Steel Cyclone Combo enhances enmity gain.

MNK and DRG specialize in dealing damage. Even if they have lower HP pool, they have hate reduction ablities, which raise their max dmg output cap (until hate shifts). They also have ablities that further boost their damage to reach that higher dmg cap. One could argue that WARs' Berserk is on par with MNK and DRGs' DD ablities, which it isn't imo, but WAR still loses in max dmg cap and steals hate much easier. And like I said, while using Berserk, WAR is definitely NOT in tanking state, not to mention that getting hit will gimp Berserk effect further decreasing WAR dmg output. That simply concludes that MNK/DRG>WAR for DD. Why is this even a discussion?

WAR tanking and using Rampage is balanced with MNK and DRG, because then they don't have to worry about keeping their enmity down.