Why is anyone unable to think of their own?...+HP does NOTHING in making you a better tank. The argument that it will be easier for healers to keep you alive, cause they have a "bigger timeframe" of keeping you alive, since it will take longer to die doesn't help you tanking and in fact doesn't help the healer keeping you alive.

This is all due to WoW, where HP became the main factor of surviving as a tank...

The only reason this trend is going in WoW, is cause Raid boss' can two hit you...therefore having an HP pool that gives the healers a bigger timeframe in which they can react is vital...this is not the case in FFXIV. There is roughly anything that will twohit you, therefore having a huge HP pool does nothing for you or the healer.

It's about damage mitigation, cause the more you mitigate, the less the healer has to heal over time, which reduces his overall MP usage, which is far more important in boss fights.

Until there will be bosses that can twohit you constantly, there is no need to go all out on HP+...in fact it will make you a worse tank, then someone with maybe 200HP less, if he takes less dmg over time.