Plus, the overly-simplistic analysis used by many of the "healers is broke" crowd overlooks the fact that sometimes, the best contribution we can make to raising team DPS (i.e., to lower the clear time) is to heal.
I first started thinking about this when one of the healers-is-broke crowd ranted about how he wasn't going to reduce his DPS by taking time off to heal a DPS that was intentionally standing in mob AoEs. "It's not my job to make his parse look good" was the complaint.
But consider this situation: there's a Reaper doing her single-target rotation: Slice - Waxing Slice - Infernal Slice, average potency 1140/3 = 380. If she has to step out of range of the target for a GCD to avoid an AoE, that's on average 380 potency (and 10 soul gauge) lost forever.
But let's say she knows her healer will support her, and stays there, killing the target.
And let's use the worst case, that the healer uses a GCD heal on the Reaper, giving up a Dosis, Glare, Broil, or whatever.
That's about 300 potency, give or take, worth of Healer DPS lost -- to gain 380 potency of Reaper DPS. Even assuming that the damage/potency ratio is the same for the two, that's an substantial gain in team damage. (When there are multiple melee DPS and you can AoE heal them, the DPS balance shifts even further in favor of healing them through the AoE.)
Realizing this, and recognizing that a lot of the incoming AoE in the game is piss weak, I've outright told melee DPS: "for this boss's AoEs, feel free to not dodge if it means staying engaged, I'll keep you up." Because it's a net gain for the team, even if my personal DPS goes down.
Making decisions like this -- employing tactics like this -- are part of what makes healing fun. No other role gets to do it.
And the healers who are too selfish or stupid to prioritize the team's total output over their own won't even think about doing it. Obsessed with their own DPS parse on a class that's not designed to DPS, it's no wonder they are unhappy.