Once again, warriors are just different. They require a different play style from the healers and the tank themselves. If you compare only on paper, you're going to miss the key strengths of the warrior job.

On paper, you have to make it as simple as possible. Warriors require 5% more healing, but have at least 25% more health. 95% of the time, that 5% more healing isn't really important... because it simply is not very dangerous or threatening. But, when you look at the points where it is very important, you have a skill that provides 1-2k HP instantly; and, which you can usually apply at such times back to back for up to 4k healing done in a pinch. Because in tanking endgame right now it is ALL about those critical short period of time where you face any danger at all. Utilizing these heals with the right timing can make it nearly impossible to kill you under most circumstances.

Warrior is a VERY strong tank in endgame, but most of you don't understand this because you haven't been there.