That's what I believe the healing model is at the moment. The fight most healers hated because it did not feel right to keep everyone at less than half health and in some cases people died from debuffs. I did Heroic Blackrock Caverns where the Forgemaster does an AoE to the raid and then summons adds meanwhile the tank takes massive damage. It was pretty much like Anub'arak because I could not afford to keep everyone above 50% or the tank would suffer and die from me being oom.
Once I found out how to heal this way as Discipline it seemed enjoyable for a while but what bothers me is if anyone takes too much damage or the tank does not understand the mechanics we will end up at the graveyard along with everyone else. There should at least be a repair cost reduction for healers using the Looking for Dungeon tool or something.