Quote Originally Posted by Exiled_Tonberry View Post
Either way, something has to change in raiding that forces players to mix job compositions.
Not much to be done there except forcing every raid party to take X, Y or Z job just in order to clear. Mitigation and Healing are artificial additions and as a consequence only ever as useful as they are required, there's not much you can do about that - You can require more or less of it or you can invalidate Damage as Winning Condition. You don't have more options.

Every "utility" you give jobs is measured by the same standard. As such, the "defensive jobs" as you call them need either more direct DPS done by themselves, or indirect DPS via party buffs. It is as simple as that.