It's harsh alright, but I still fail to see the truth part. PLD is a great defensive tank and takes less damage than all these jobs, MNK may be arguable (and situational), but especially with new PLD gear I'm positive they would still take less damage in most cases. And Defense does play a role, if not a huge one. As I mentioned before, Defense needs to be adjusted to provide more of a difference, it's a flaw with the game, not with PLD. Still, PLD has plenty of JAs and spells and especially equipment that drastically reduce the amount of damage they take. Shield blocks play a huge role in that, enhanced a lot by Reprisal. Phalanx helps a good deal on certain mobs as well. Sentinel and Rampart are great, although obviously on a timer. Even Flash helps, I've avoided more than one hard hitting TP move in my time with that.
And check out their gear, even without Ochain/Aegis. AF3 set reduces up to 15% damage, not counting the high Defense, Vitality, Shield Skill, Shield Defense Bonus and an absorb effect, which is another factor (5%, which does not count towards the cap), which adds even more in damage taken over time calculations, since it actually cures you. This is especially nice in solo situations, or lowman without a healer, when damage taken over time matters a lot more. I've seen a PLD solo King Arthro at 75, I don't think a MNK could have pulled that off, even spamming Hi-Potions, which still wouldn't be the same.
I doubt a lot of people have tried PLD tanking in Abyssea, because there's simply no need for it. But calling it worthless is just wrong. I've blood tanked inside and outside of Abyssea with 100% success as far as I can recall. Even if it's not the best option in many cases, how does that make it worthless? Maybe your definition of that word simply differs from the actual definition, without value/merit, not contributing. Both of these things are objectively wrong for PLD tanking. This is not a matter of opinion. And it's not the first time you deemed something that isn't the absolute perfect solution worthless.
Arguable, personally I don't wanna deal damage comparable to any actual damage dealer. It may be a solution, but not one I'd be happy with. Rather improve the tanking aspect, or rather, reestablish the tanking aspect, as it's been lost in the depths of Abyssea. These days people call any DD that can keep hate through cure spams a tank. This definition is the only thing that's wrong with PLD's standing in the game. Once actual tanking will have a meaning again, PLD will be sought out again.