And even then, PLD wasn't exactly a requirement for any of the old content. It acted more of a safety net for alliances that weren't at the top-end and couldn't zerg down NMs. So even when PLD was at it's prime, it wasn't a top-tier job.
This is hugely important. It mostly emphasizes the plight that tank jobs face. PLD is a tank period, it offers a group nothing else. It can not be a place healer like a RDM or a DD like a DRK. It is a tank it is its only purpose. A couple years ago SE made a nerf, that targeted RDM mostly but the lesser used DRK.
In a zerg situation a DRK even without a KC was capable of not only taking hits but dealing massive amounts of damage over a short period. It wa the corner stone of zerg "tanking" because it was hard to kill, and dealt massive damage. Not to say PLD wasn't involved, many shells used PLD to take initial hate on a mob through is large VE infusions, but not expected to hold.
In contrast you have RDM that was used not to deal damage, but to maintain a mobs focus over long engagements. It had limited VE abilities, but it had the best TE rotation at the time. Once a RDM established hate, it was almost impossible to remove that hate. RDM would bleed little to no CE, and had a cycle of several highish VE spells the could spam.
Both were nerfed because they we to good. RDM lost its CE+VE generation spells, and DRK lost its ability to handle itself in a DPS race.
PLD has never been the ideal tank. Throughout this games history players have gone for optimal grouping. A PLD = RDM, DRK, NIN, THF. and the latter 4 allow for more useful flexibility. a RDM supports better than a PLD, a NIN DRK and THF out DD a PLD, and bleed less enmity in longer fights.
PLDs use is really nonexistant if you think about it, even in todays game, it is most unfortunate.
I would almost wager that giving PLD a large boost in damage potential would be its saving grace, then again SE could try another nerf, like they did to NIN, THF with the AoE additions, or they did to DRK with the BW reduction (and again I think I got the wrong ability), and like they did to RDM and DRK with the enmity change to enfeebles.
Enmity is **** and really SE has IMHO tried to tweak it to far in PLD's favor, by removing realistically a good 5-6 tank options (RDM, DRK, NIN, THF, DNC, SAM)
Yet they never understood the root issue with PLD....It is not a great tank, it has had some moments, but overall even in its heyday, It required specific tanking support (turning backs not nuking, etc) It wasn't because the other tanks were to good...its because PLD sucked.
Having to take hits in order to effectively increase enmity is bad design.