Why are healers more populated than tanks?

[Nicodemus_Mercy]

'Tis something I'd been curious about for a while, and I couldn't find any answers on reddit or here on the forums. Why are healers more popular than tanks? Just my personal opinion, but it feels to me that healers have a more demanding job, especially in 24-mans and end-game raiding, but again, that's just from my own personal experience. Forgive me for my lack of MMO knowledge, but this is something that has been something of a curiosity for me.

I think its a matter of responsibility.

In order of "level of responsibility" I rate the roles as:

Tank
Healer
DPS

The tank has the most responsibility. They are expected to lead the party through the dungeon and set the pace. In higher end content they are also expected to contribute a certain level of dps. Not everyone is comfortable with being in a leadership position, I know I'm certainly not. I can tank, but I prefer to heal. I like being in a more "advisory" role backseat driving rather than in the front behind the wheel. Tanks are also melee and not everyone is comfortable in melee.

The healer has the next most responsibility. They are expected to not only keep the party alive and healthy, but also generally expected to contribute some level of dps in most content. This is the level of responsibility I am comfortable with. I prefer being at range with a clear view of the battlefield so I can accurately assess whats going on and make the best choice I can to adapt to it. I like being able to sustain and support my party and allow them to take on threats none of us could on our own. I also like that while I contribute dps, I am not scrutinized with a magnifying glass about it. I prefer not to engage in pissing contests about dps.

The dps has the least responsibility. That's not to say they have none, but rather most of their responsibility is personal. Stay out of the fire, be at the right spot for the mechanic, click the thing at the right time. Obviously the primary responsibility of the dps is to deal damage which is also the easiest metric to measure thanks to 3rd party parsers. Many like seeing their name on a meter with big numbers and especially like others seeing their name at or near the top of that meter. Barring clutch resses from certain jobs, the dps basically don't have to do much that's different from what they do solo, blow stuff up and stay alive. Generally speaking, they aren't responsible for leading or controlling mobs and they don't have to worry about keeping someone else alive. They just have to pew pew, do the mechanics that everyone else has to, and stay alive.

Being dps is the "easy" choice. Not to say that being good dps is easy, it certainly isn't for everyone, or even most people. I believe healers end up outnumbering tanks because they are at the sweet spot for "responsibility level" and also don't have the same kind of complexity or pressure to perform as dps do.

There's also visibility/impact. When a tank can't hold threat, or gets destroyed by certain pulls/mechanics you notice, especially if it causes a wipe. When a healer can't keep up with incoming damage, or fails to avoid mechanics and dies thus stopping all the healing and causing a wipe, you notice. When a dps does a crappy job and/or dies, yea you notice but just grumble about it while the healer and tank slowly whittle down whats left while giving the dead dps the stinkeye. Or worse in high end content where dps checks are prevalent, the whole raid will pour over the meter to find out who the "weak link" is.