It honestly worries me to read a response like this from the developers. I feel the changes they made and their reactions to criticisms both show a lack of thought, which in a game where they show us just how much though they have (and its huge, to be clear, I love FFXIV) is really strange.
A tank primarily hits buttons to hit an enemy in combat, as such they *want* to do damage. Limiting our contribution to damage to being minimal makes the job not fun or engaging to play, which is bad for a game that has such a high tank to no tank discrepancy that FFXIV has (more than any other mmo ive ever played, swtor/wow/tera/AoC/Warhammer/etc). No one says they should top meters but that isn't the case anyways, and even in 3.x the only time a tank was beating dps was due to gear and skill discrepancies--which is fine.
The easy solution is to use the 3.5 damage calculations. It ensured that tanks 'wanted' tank gear, where before that any tank went with slaying or similar because the truth is we don't *need* that extra hp, if you understand your class and the healer is not brain dead, than FFXIV works around damage 'mechanics' which you can mitigate down to being negligible. The only time health otherwise makes a difference is to cover for errors, which are only important while learning a fight. After mastering mechanics more dps results in shorter encounters, less strain on mana for healers, less chances for things to 'go wrong'. Offense is effectively a defense as long as you can comfortably survive the stressful mechanics.
So yeah in the end, HP Inflation as a statement made zero sense. Every new set of gear increases our health, and we have no choices around that. So what exactly is being inflated and why would having vit contribute to AP cause it to inflate more? You cant use slaying pieces, so melding vit is basically non existent.