warrior burst does last past banner, banner is only a part of the burst. and to say to just "kill it" is nonsense. it has like 130k health, and to try and kill that while your being tunneled by a warrior when it only lasts 6 seconds is stupid. totems have 5 health.
and saying that banner is the only thing that gives warriors high damage is rediculous. avatar lasts 24 seconds and is a 20% damage increase, along with recklessness which is 50% chance to crit increase. crits are 200% damage increase, so you might as well be doing 240% damage a swing.