The biggest problem with all of this argument is that people play to put up numbers: DPS put up red numbers, and healers put up green. But this simply isn't the case, and shouldn't be for any content not involving a raid boss (and sometimes not even then). First of all healers are *not* HPS bots... and anyone actually involved in playing a video game should be ... ya know, engaged. Just like it make sense to not stand in fire (because in other games fire usually kills you), a healer should do their best to be proactive... when I go into a dungeon I Holy each group of monsters at least 3 times, becasue I know how Stun and other debuff duration works. I'm in Cleric Stance while I use Holy because the monsters are stunned means the tank doesn't take damage. If I have to heal someone an I just turned Cleric Stance on and someone needs to be healed, I'll cast Stoneskin becasue I know that Stoneskin isn't affected by my stats. I know that if a tank doesn't have to move and fighting a boss that uses Disease, I can just Divine Seal + Regen and perhaps Medica2 up so I can save casting an Esuna. When I run a dungeon a second time I use forsight to know whats coming and how much mana I'll need. I also know that if the tank pulls the next group of mobs and I want to regain mana and doesn't need to be healed, I can just stand there and get "out of combat" regen. I make frequent use of HQ X-Ethers and HQ X-Mind pots, especally with Presence of Mind. I keep the tank targetted when I spam Holy so i can Benediction and keep spamming it, I keep bosses on Focus Target so i know when to Virus or Surecast a Medica. I use HQ 2 star food in dungeons and raids, sometimes better. I use Fluid Aura on a monster no one is attacking to save the tank 6 seconds of damage, or on mobs that don't get knockback, or to disrupt a nasty move or move a monster out of a buff zone. In low level dungeons I attack the mobs in the order the tank marks them. I know how my abilites work, what they're limitations are, and I practice things until I can get it right.

However, none of things are the mark of a good healer, they are the mark of a bad player. A WHM who DPS's like a bad DPS isn't and different than a BLM or NIN who DPS's bad.
A bad healer is also going to be a bad tank, or a bad DPS.