Question to healers

[Dyvid]

I have been noticing that more and more healers are letting the tank stay at lower and lower HP so they can DPS. 50% is fine. Most dungeons don't have attacks that can kill a half life tank. 20% and less is what I'm seeing more of.

My question is why? I want to hear the points of view so I can understand.

(Note: that very rare times I'm watching the tank die, very rare)

Name of the game is speed runs and healer's AoE attacks is a good source of damage. So healers try to squeeze out every ounce of dps they can before taking a break and healing the group again.