Every like or dislike is subjective. But when you objectively have far more people seeming to like set A over B or C, isn't there quite likely to objectively be something subjectively attractive that is lesser in set B or C relative to set A? If no one likes your food, it's not that your customers are all quirky or tasteless people; it means simply that your food is bad, at least in what's important -- attracting your target customers.
Yes. Agreed. That's... what I just said....
But just what responsibilities would that 1-in-3 DPS have that he didn't already have, identically, when 1-in-4? The problem is the visibility of responsibility, the shorter-term benchmarks such as "did this die quickly enough not to wipe us?" As healers and tanks contribute to that in functional identical manners, just with additional utilities, reducing total party dps does not make the DPS's responsibilities any greater in practice. There's no functional difference, and no change in how easily his mistakes or successes are noticed by most other players.Perhaps if the responsibilities of DPS were equally visible, a bit more of the ostensible tank/healer burden taken up by DPS, then the other roles would be more attractive, at least relatively.
And I mentioned it because I don't understand why it's shocking to you, save that perhaps you're too hung up on the idea of set role allotments despite varying strategies. Be it here or in a table-top game, the only throughput that ultimately wins fights is damage dealt. Tanks and healers both require damage to be taken to see any use, and the less damage you have available to deal, the more damage you will be forced to take, especially against more numerous, lower-HP targets. There are far, far more choices in damage-dealers than tanks and healers simply because those two "roles" are far more rarely relevant, and can in many cases be avoided outright.
Moreover, outside of threat tables as in MMOs, tanking isn't meter-stacking -- it's just positioning. In most cases, if the enemy has to get past you to get to more vulnerable targets, that's enough. There's no enmity; just interception and harassment.
Think of the number of managers relative to workers. The purer or more numerous the managers relative to workers, the more potential labor goes to waste. Luckily our tanks and healers aren't forced to only meat-tank or only restore health, respectively, but the proportions still follow. Damage will remain the most popular "role" not just because of the aesthetic -- there are plenty of people who love the beefy plated Fighter or Paladin aesthetic -- but largely because it's the one not wastefully specialized past a certain point.
At any rate, though, the proportions given in this game is that there should be as many DPS as tanks and healers combined. Fair enough. But, again, are we running into roughly 2.3x the DPS as tanks/healers because of their aesthetics, or because of the gameplay or responsibilities? Is it an inherent love of the "DPS role" or simply a fault of the perceived imbalances between what enjoyment one can get out of a tank or healer relative to a damage-dealer. Even the aesthetic can technically be fixed, as we often saw with HW DRK and Warrior for a time, but the latter aspects are entirely up to the developers to improve upon. It's not a fatalistic "community irredeemable" thing; it's a game design thing.