It's not a choice and there are no options. All of what you have said is a fallacy.
It's the same reason why there is no skill tree in this game or why game designers are increasingly wary of providing people false choices. At the end of the day, it's not a choice because people will min-max, calculate an optimal set-up, and stick to that. There will be no variety.
The concept within design is called strictly better. DRK and WAR right now are strictly better than PLD. Now, that wouldn't be the case if PLD provided something meaningful to raid content. The problem is they currently don't.
DRK and WAR provide quantifiable and meaningful DPS increases. DRK, WAR, and PLD all have no issue surviving through incoming damage in Savage so whatever situational survivability advantages PLD has is irrelevant.
Now, if you understood anything about tanking in this game, you would know the current meta and why this type of balance was doomed for failure. The idea has always been -- meet a survivability threshold, full DPS thereafter. Tanks have been hitting an eHP threshold and then stacking DPS stats in order to push their DPS. So now, you have 3 tanks that all can meet that threshold but 2 of them start from a different DPS baseline.
In other words, blatant imbalance.
So, you might say "well, it's just the top progression groups pushing really tight DPS checks."
And...? What people don't understand is unless there is a difference in learning curve, everything scales down proportionately when judging lesser players. A DRK in the hands of an exceptional player will perform exceptionally. A DRK in the hands of a good player will perform good. An exceptional DRK will out DPS a exceptional PLD. A good DRK will still out DPS a good PLD. You cannot balance around different levels of skill. You might say "well since everyone will have more gear, it shouldn't matter." No. Gear effects everyone equally. A DRK with an esoteric weapon will still out DPS a PLD with an esoteric weapon. "But DPS will be better geared now so tank DPS won't be as necessary." So... basically a PLD has to rely on their DPS carrying them to their clears? How is that balanced or acceptable?