Quote Originally Posted by Shurrikhan View Post
So why should the one role that gets its entire unique functionality for free output more than the one that does not?
Probably for these very reasons.

Healer DPS and GCD healing compete for usage (In an ideal world where healing isn't 99% free because leloGCD's). Thus, if Healers do more DPS, then there puts more focus on Healers actively avoiding their primary role to DPS more.

Meanwhile, with Tanks not having any resource competition between their Tanking and DPS skills, having higher DPS doesn't necessarily detract away from them performing their primary role.

This is an oversimplification, but from a design standpoint, you don't want the role that has competing resources to have more efficiency with their off-role causing conflict within gameplay.

There are however, other things that can be considered in regards to this too, such as the minutia of such a scenario where if healers do more DPS than Tanks, then Tanks sacrificing DPS for more mitigation in order to allow for more room for the Healer to DPS can be a thing (As opposed to the Tenacity issue, we currently have, where the DPS loss from melding Ten over Crit/DH isn't mitigated by the DPS gain from healers pushing out more DPS GCD's (Partially due to the fact that it outright doesn't even mitigate a GCD spent on healing)). Though, such a scenario would need to actually have any sort of interaction with mitigation beyond maybe melding Ten/Det over Crit/DH and then still just mashing max DPS combos during fights anyway.