Although it may not be much, don't forget Warrior's Thrill of Battle (push it to the EHP limit yaaar!)

I think what I'm partially seeing is closer to the "enough HP" for players, pre-Binding Coil. But with random players, I can see that having that high HP, particularly as a Paladin, can boost random player confidence at this stage. And confidence plays a role, as once players start panicking, and/or expect negative results, they tend to play worse and may even blame their own shortcomings on the tank's HP or gear (even if all three are true).