There's a really thorough and thoughtful thread on PLD on the FFXIAH site that goes into a lot of ideas and thoughts about PLD's current lackluster state. From my personal point of view, I think it can all be summed up by the following: RUN has better job abilities, REMA weapon, utility, threat generation, and damage than PLD, with roughly the same damage mitigation (passive or otherwise) overall. In a world where this is true, there's no incentive to take a PLD over a RUN for any content. The issue isn't necessarily mitigation (although I'd love to see shield block rate become a part of an overall PLD adjustment), it's that RUN is so much better in almost every regard that when you're trying to run as efficient a group as possible, the choice is easy. I really do hope the developers read these forums, because as it is, they've done nothing to help PLD since they've elevated RUN to such a powerful job, and that's really disappointing design.