This week I was reminded that even though I love healing, there's something about healing twenty-five-man raids that makes me seriously cranky, and I'm afraid that something is the other healers.
Healers are supposed to be a team, but I rarely feel much team spirit in anything larger than a ten-man. I think it's because two important factors for a team operating smoothly and successfully is that everyone can be relied on to take care of the tasks that they've been assigned and to pull their weight, and that everyone gets along reasonably well. It's not completely impossible to lead your team to victory with one half carrying the completely useless other half, and both halves hating each other's guts, but it's unlikely to be a pleasant experience. And isn't that what raids are supposed to be about? Having fun?
To address my second point first, the desire for everyone to get along, this is something that I never felt that strongly when I was raiding as dps. Sure, it's not nice when you've got someone in the raid whom you don't like, but as dps you're rarely forced to interact with them all that much anyway. There are a few fights that do require a high level of coordination among the dps, but most of the time you'll be fine as long as everyone just does their own thing correctly, which means shooting the right mob and not standing in bad stuff.
On the surface, healers operate fairly independently as well - X on tank, Y on healing the raid - but in truth it's a lot more complex than that. Some class abilities pretty much ask for cross-healing: of course the resto shaman's chain heal is great for raid healing, but he might as well keep an earth shield on the tank at all times. Also, in most encounters the amount of damage taken by all targets rarely stays the same throughout the whole fight, so when there's little to no raid damage going on it makes sense for the raid healers to help out on the tanks and vice versa.
Now, you could argue that optimising the teamwork in such situations doesn't really require you to like the other healers, but I've found that it helps a lot. With some I've even had such a good connection that I could predict pretty reliably whom they'd heal next at any given point and direct my own heals towards another target in the meantime. There was a question in Miss Medicina's healing questionnaire that asked which class you enjoyed having the most as your healing partner, and from what I read in some responses I wasn't the only one who ended up naming classes with whom I had played well in the past simply because I knew the other healer well and we got along.
The point is that healers are forced to work together very closely at all times, and having to do so with someone whom you consider a stupid tit is both detrimental to your performance as well as all around un-fun. Some of our recent recruits make me want to hit my head against my desk repeatedly sometimes, but what am I supposed to do? It's not like I can just ignore them, due to the nature of our forced cooperation.
As far as being reliable and carrying your weight goes, this is another thing that I've found a lot more painful to bear as a healer than as a dps when it goes wrong.
Let's say you have two dpsers, a warrior who does 8k dps and a hunter who does 5k. Assuming that the hunter isn't just standing there twiddling their thumbs but is genuinely trying and simply doesn't have an optimised rotation and the best gear... the warrior is still doing more "work" so to speak. However, as long as the boss dies it doesn't make that much of a difference. It will take longer than it would have if the hunter did 8k dps as well, but the longer fight time shouldn't put too terrible a strain on either of them as they can just keep going through their rotations.
If the boss has an enrage timer and you end up wiping due to a lack of dps, the warrior will have reason to be annoyed with the hunter, but he won't have to feel at fault himself. He might be able to squeeze out a little more dps with a consumable or a cooldown here or there, but most likely not the 3k extra that would be required to compensate for the hunter's lack of damage. Basically a good dps will always be doing as much damage as he can, and whether others do the same doesn't affect him much unless you hit an enrage timer. Even if he "compensates" for another dpser doing less, it doesn't actually make a difference for the way he plays, his rotation stays the same.
Now, healers also have a hard cap for how much healing they can do, assuming they use all their biggest heals non-stop until they are out of mana. On my priest this currently seems to lie somewhere between 6 and 7k hps. However, most encounters won't require your healers to spam all their biggest heals from finish to end, instead the damage tends to be concentrated on specific people (the tanks) and phases. That doesn't mean that healers are lazy for not giving their all at all times, but that they are simply limited by how much damage is actually being taken.
At any time during which I'm not spamming heals to the max already, there is still room for me to increase my output. However, this is generally not pleasant - unlike a dps who can perform at his best by following a rotation or priority order, pushing my maximum healing output means that I'm playing whack-a-mole on speed, constantly forced to make split-second decisions that can spell certain death for someone if I make the wrong choice. Having a certain ebb and flow in the healing required during any given fight is one of the things that helps to keep healers sane.
Now, let's assume you have two people on raid healing. One of them uses the wrong spells for the situation and gets a lot less healing done than he should, what happens? Well, the damage is still there and needs to be healed, so either people will die from it, or the other healer steps up to take over, increasing his healing output per second and the associated stress. Unlike a strong dpser, who can "compensate" for a weak one to certain extent without making any extra effort, one healer compensating for another's lack of healing directly results in more work for the one doing the compensating. Not pleasant, but sometimes that kind of thing happens - also when one healer dies during a fight for example.
However, when you have to put up with this kind of thing raid after raid because members of your healing team refuse to listen to advice and outright ignore certain instructions, it becomes incredibly off-putting. Every bit of compensating you have to do comes at the cost of your own fun.
I remember helping out in a TotC10 run once, where I was supposed to duo-heal the instance with someone's pally alt... but the guy had no clue how to heal as a paladin and did almost nothing but spam flash of light. By the end of the run he had done less than twenty-five percent of all healing done. One of my guildies looked at the healing metres, laughed and congratulated me on my imbaness, but I was not amused. What had been intended as a bit of assistance on a relaxed alt run had just ended up stressing me out immensely, as I had to heal the whole raid almost entirely on my own.
Similarly we recently recruited a healer who's an okay guy and certainly not a terrible player, but he just doesn't seem to entirely "get" healing as his class, keeps using the least optimal spells and comes out of every raid having done half as much healing as other people on the same assignment. Friendly advice seems to fall on deaf ears. Why did he pass his trial then? I don't know, but our healing leader simply tends to make odd decisions like that.
The point is, healing twenty-five-man raids bugs me because there are so many more healers there than in a five- or ten-man, which drastically increases the chances of having to deal with bad apples. And as a healer dealing with such bad apples means having to listen to everything they say (no matter how stupid you think it is), and sacrificing some of your fun to make up for their incompetence if you don't want the raid to wipe.
There's no "i" in team, but there's a "me" if you mix it up a little bit, and that me is really starting to miss being dps and not having to personally deal with other people's failures all the time.