Outnumbered two to one
There are currently four tanking specs in the game, out of 30 possible specs. This is the lowest number of specs per role. Healing has five (discipline and holy priests, resto druids, resto shaman, and holy paladins), and DPS has 22, because one of the tanking specs can also be a DPS spec (the feral druid spec). This points to an already obvious fact: DPS specs outnumber the tanking and healing specs combined by a two-to-one margin. Why is this?
Well, for starters, while healing makes a certain amount of sense to people who've played other games, the idea of the tanking figure is fairly unique to the MMO genre and has more or less existed in that genre to help make up for the games' lack of intelligence. The original tank and spank encounters were designed around the idea that the game needed help to decide who the monsters would be hitting. After all, their roots are in pen and paper RPGs like Dungeons & Dragons, but there's no game master to tell the monsters what to do.
With modern encounter design often varying wildly from this formula, one of the reasons for the tanking role has been changed or removed. Tanks often find themselves switching targets, rounding up adds, taunt swapping to clear debuffs, kiting, and in general working on aspects of a fight far removed from the old keep the big, ugly thing punching me instead of the mage aspect of the role. This complexity was even mentioned in the recent Dev Watercooler as a reason that threat was being increased so that tanks don't necessarily have to worry about threat races or having to switch targets to intercept streaming adds.
Class archetypes and character preference
Let's consider, however. With four tank specs and 22 DPS specs, we're already at a significant disadvantage in terms of picking a character that tanks versus one who does not. If you enjoy certain class archetypes such as the demon-worshiping spellcaster or the companion to animals, you're locked out of the role even if you'd like to give it a try. Of course, the argument can be made to roll an alt, but if you simply don't like death-channeling necromancers in plate or turning into a bear, then you're not going to want to do so just so you can tank. Furthermore, there are people who play those four classes who simply don't find tanking as it stands particularly compelling.
There are ways to do without tanks, of course. One way would simply to make healing changes that allowed healers to cope with a boss's switching to whoever had aggro rather than having to have a limited number of people who are talented and geared to make healing them easier and who chose abilities and stances to make enemies want to hit them. Another way would simply to make tanking a choice a class could make by picking a stance, form or presence and opening it up to more classes -- a simple trade-off (you chose to tank, you do less damage and generate more threat) that makes all sorts of classes able to tank who never tanked before. There are plenty of classes that have abilities that could be used to tank -- warlock Metamorphosis, hunter pets, shaman weapon imbues like Rockbiter and their earth elementals -- with a little modification.
What change would be enough?
Whether or not either of these options or any others are really good for the game is what should really be discussed. Is it simply a matter of not enough tanking flavor, and can that be provided without messing up tanking balance? Should tanking be reduced to a simple toggle that more classes could flip, or would that water down tanking too much? Is tanking integral to the game or an outmoded idea no longer relevant with fight design as intricate as it has become, and can you get rid of it without rendering leveling content trivial? Tanking has been with the game since its inception and has seen a lot of design work to keep it a vital role, so abandoning or redesigning it to this extent would be a huge decision. But right now, it's no longer an unthinkable change to the game.
We've tried bribing tanks, changing CC, letting the instant queues tempt them, and even reducing how much they have to juggle to get them interested. Is it enough, and even if it is, is it a sign that tanking simply isn't worth the hassle?
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