That idea fails to address what Cream_Soda has been saying all this time. I'll reiterate it in a different way so maybe people will get the point.
We do NOT need help holding hate. We never did.
What we need is a reason to have a PLD in the party instead of a DD tank. Justification.
Holding hate 100% of the time might make you feel like you're tanking... but really, what's the point? If a DD, even a sub par DD can survive the mob's damage and deal more damage than you, they speed up the fight. And as we all know in abyssea, time is money. The playerbase doesn't want a safer fight, they want a faster fight. So how can PLD speed things up?
Damage.
It not only speeds the fight up, it is easily the best hate tool in the game. I'm not saying that we have to upset the job balance and become the #1 DD's as well as tanks (although elitist mentallity will take nothing less than #1... but there's no satisfying them anyway.)
Any type of dmg buff would be a step in the right direction, no matter how big/small it is. If you're dealing significant dmg to help speed things up (and tank), that's all anyone can ask for.
And as the icing on the cake, how about a little perspective?
Even RDM has Composure (it's used for buff duration, but it does give them accuracy.)