The active mitigation model is largely proving to be no better. WoW is proving this as I speak. You end up doing the same thing; it's just that CDs are more frequent & less powerful, while giving you tools that both do damage and increase mitigation. However, look at Warrior Tanks in WoW or how the Lancer in Tera works. The former example is very clunky, while the latter example relies on the player actively using what boils down to the "dodge button". Active mitigation is HARDLY what it's cracked up to be.
In WoW & Rift & Tera, it became a dps game for tanks too. Don't kid yourself. Just because tanking in WoW as a Death Knight or Druid meant self-healing doesn't mean it wasn't a dps race. If you want to play a game where tank damage is irrelevant, then you better go play on some Vanilla WoW server, where people care more about nostalgia than actual damage.the actual act of 'tanking' is incredibly boring, leading you to mostly just joining the dps to race to kill the boss. In other games, a great tank can heavily reduce their incoming damage second to second with great skill---and while damage does come, its secondary after actively mitigating down the incoming damage.
In the active mitigation scheme, the damage is largely mitigated by using your most damaging abilities OR tank damage is so ungodly low that tanks don't even try to do anything other than basic damage. So, in other words, depending on the way it is implemented, either tanks who do bad damage are also bad at tanking OR tanks who focus on damage over mitigation are dead. Either extreme is really not a good balance. The former extreme results in the same kind of dps races that we have in FFXIV, while the latter extreme means that tanks are generally bored and constantly going, "My CDs that requires 5 stacks of X is now up for 5 seconds. (Snooze)".
Fact is, while tank itemization is a problem right now in FFXIV, tanking in this game is relatively well implemented compared to other games. So, before you go crapping on tanking in FFXIV, go tank in the games I mentioned. It all equals out to be about the same end result. You still use every GCD to ensure you are doing max damage. You just have different skills and your damage scales based on how the devs in that game decided tank damage would scale.