Tank homogenization

[Absurdity]

Um.... You literally can face tank it with BIS gear, even the Melee DPS can in 5.2 easily discovered by top tier raid groups. Originally Paladin covered a Melee, pushed on further by having a 2nd melee soak a blast too for major uptime.

Yes, and now read what you said again... in organized groups and BiS gear you can "ignore" the mechanic...which means the intended way for it to be done is have the tanks stand at the edges of the arena, doing nothing, to not cleave the raid to death.
That is simply terrible design for a mechanic, whether or not players figure out a way to simply not do the mechanic as it was intended doesn't matter because SE does not design fights with uptime strats in mind.