I don't see how it's debunked. If the damage a tank is given allows the team to STILL Clear, a DPS slot is going to be taken, how is this hard to understand? If you can still clear with a third tank, why would you not take it instead of say, MNK, or at this point Ninja which was the lowest DPS I saw for a bit. Yes I'm taking into account Party Diversity Bonus for this. If you can clear with 3 tanks, why would you not take 3 tanks? People will use the easiest, most practical, and most consistent way to beat a fight; that's just how things are. Look at people complaining about the DPS teir lists and BLM being basically a must pick these days because the math shows it's good so the community follows. I've already covered this before, people will follow the math.
And if the math ever comes up that 3 tanks is better, safer, and more consistent way to clera; guess what the meta becomes. I don't think this is hard to understand; if there's little to no difference between the end result, a tank is a better choice as it can eat a DDR mess up and not instant die.
Look I don't think either of us want to go through FAUST again, regardless of your skill level. I do agree that tanks are currently in the easiest time to DPS. Healers might actually be even easier given their heals are so strong they can find more than enough time to DPS, which is part of their problem but that's a separate problem. But no, we can't have Healers deal more damage than us because the Devs messed their role up, we simply need add more damage to Tanks because that's the only acceptable solution. No Healer should out damage us!(sarcasm).
Something people don't seem to understand is that Healers out damaging us is more a problem on the Healer end than on the Tank end. I'm pretty sure the Devs didn't go into this expansion with the idea of making Healers out damage us, no the idea was different if I recall. The idea was to make their damage skills hit harder to make up for the fact they'd be healing more often. More damage, over less hits. That was the intent I believe which if I'm wrong, I'll own up to that but that's how I absorbed that info.
And we all know they messed that up. Being higher on the damage chart is a by product of the devs not understanding what to do with Healers. Put a different way; how many people would actually be happy if Healers were nerfed into being below us either by fixing their game play(Having to use more GCD heals) or just lowering the damage numbers? Would people still be asking for Tank Damage buffs?
We all know the answer here which is Yes. So quit blaming it on the Healers.