Tanks are the last person standing by a "mechanical" need (1 of healer jobs is to keep them alive so the mob/s don't dmg them & DPS to 0hp) so a Tank being alive last happens more often (cept in derp-tank times dieing to 1-shot mechanics) I mean I almost did what that WAR did as PLD on my 1st time run of Weeping city... with only that fight as my info about boss mechanics (granted my run was from 3% & I died at 1 due to it being my 1st time fighting here so lack of skill with mechanic's killed me)

Finding a WAR user skilled enouf to live & win in that senario is just as awsome as finding a PLD or DRK that can to, there Tanks DEF mitigation & "turtling" is in there job discription FF14 just gave them a way to "heal" in burst's... heck for a Tank doing that is "mentally" like fighting off a trainwreck in slow-mo, a "War of Attrition" if u will (pun intended for OP's case)