This thread is a bit hard to follow but I think I'm seeing the OP's and supporter's points as being that they just want tanks to do a bit more damage so that they feel that the work they're doing is properly valued. I'm not going to comment on what aspects of tanking or healing feel valuable since I very rarely play these roles and do not have an informed opinion, though I am curious to hear opinions of others when framing the overarching question in a particular way:

Does this lack of value have anything to do with the inevitable power creep of the savage tier? Comparing the start of the tier as a fresh 450 to re-clearing things at 470, or at any point in between, do the tanks that want their damage to be higher feel less valuable at the higher item level or have you felt less valuable from the start? In other words, did these feelings of being undervalued come right away or have they come about after many weeks of growing stronger and not seeing the desired feedback?

I am also curious to see how people feel about that considering that an ultimate challenge is on its way, where there is no power creep shy of job changes in future expansions. Would tanks still feel undervalued dealing the damage that they currently do while being asked to perform their role in this highly tuned setting? Of course, there's no way to predict what this challenge may offer but being that it is supposed to be the most involved content presented to the players, I would say it's fair to assume that each role will be pushed to its limit.

I do ask these things as genuine questions because I find this to be an interesting topic.