Really? So an augmentable drain ST attack, a drain AoE, a drain ST attack with an attached mitigation duration, and a physical-damage drain duration buff are EVERY POSSIBLE variant by which a drain might be used in a job?...
Haven't you seen at least that many player-made suggestions for new and unique drain ideas just across the posts you've frequented over the last couple years?
I actually spent even less time in Defiance at launch as after the buff. Maybe damage just didn't have such a negative connotation then? We didn't feel the need to call raid dps contribution a matter of digital genital stroking? Heck, I did most of my tanking against 1-3 mobs in Sword Oath from day one at 50 on Paladin unless my healer could dps to compensate, and it took until 2.3 for that to be called "epeen". I don't know, but I generally saw less Warrior tank stance uptime—whether that points at dps prioritization or not—when Defiance was released, because it was simply weaker then.
I usually kept it up enmity and into the first or second Regen, then brought it back up several GCDs before I figured combat would end if needed in order to open the next pull with a larger healthpool and shields, especially to give time enough for a full Bane if Lustrate and/or FI were down, but apart from that, the bonus just wasn't nearly as worth the damage penalty until it was buffed in 2.1, making it used less. Of course, I often held onto full stacks more often too, when the bonus external healing received outpaced my internal healing generated via Inner Beast and I was dependent on direct spell healing (no same value Lustrate to cover the gaps as I regenerate stacks after using Inner Beast to save myself).
I have no idea know what intent you think that "poorly implemented system" pointed at though. Was it poorly implemented because it took longer to regenerate full effectiveness, despite already having a cooldown, and because it forced a restart on every use? Or is it just a "poorly implemented system" whose intent you applaud on the assumption that it kept Warriors from leaving tank stance as often? (It didn't. It did the opposite.)
I get that, but... If the PLD is hiding behind his shield, the DRK behind his sword, and the WAR behind his 'manliness' for all the same sort of mitigation and eHP, what if any difference in playstyle does that really create?
Going back to when we were talking about tanks on another thread, I can only say, if you dress up a shielded tank as a literal turtle but then give all other tanks the same mitigation (read: turtliness), they're still all turtle-tanks. So where do you imagine the real difference in gameplay as it applies to Warrior mitigation should come from? Raid vs. mob scaling? The pacing? What?