"You pull, you tank" is a bad mentality

[Zfz]

I believe "you pull you tank" originated from more classical (which wasn't that long ago) holy trinity games with harsher encounter requirements, such as enmity ("aggro") management, crowd control, random patrols, etc., where the actual method and techniques used to pull a pack of mobs actually mattered.

You needed to pull without alerting patrols, you needed to pull towards a place where the next patrol will not jump into combat, you needed to establish aggro in a designated order so that crowd controls can be executed (and executed such the the cc'ed mobs aren't going to aggro more patrolling mobs), and you needed to kill the mobs in an order dictated by the characteristics of the various crowd control abilities used by your party, which then would dictate the order of targets on which the tank must "work" on building enmity/threat because of the harsh threat balancing allowing competent DPS players to easily over-taunt a mob.

While FFXIV:ARR also started with those elements, justiying to a good degree the mentality of "you pull you tank" initially; those elements have been steadily removed one after another, and now it doesn't actually matter who pulls, simply because in the current content of FFXIV, there are no more patrols, there are no more places where crowd control provide any benefit, tanks no longer need to work to build enmity, and everything is an AOE-fest anyways.

So the "you pull you tank" mentality no longer has any practical applicability. It is now, for FFXIV at least, purely a question of etiquette and manners, which we all know can differ greatly depending on culture, gaming history, age, or even the mood of the player at that exact point of time.