PLD 4.0

[Reynhart]

In the very next sentence I said that was terrible design and a garbage solution to the current tank imbalance.

Which this is not. Allowing PLD to solo tank doesn't mean that it'd be the only solution or even the best.

If you bring another DRG, NIN, MNK, etc. you don't gain just the added DPS. You gain their additional utility.

It's still a matter of raidwide DPS, which is the decidibng factor of what solution is the best.
Yes, tanks do less damage than DPS, but it wouldn't be that difficult to adjust PLD so that 1-focused-on-mitigation-PLD+1DPS do the same average damage of any-tank-duo (that doesn't use a focused-on-mitigaiton-PLD).