It's all good. How you see the gap difference is subjective, and there's not much to discuss with that, seeing as it's mostly a subjective matter. What I can say is that it requires much more effort for a tank to do 1.1k DPS than for a DPS of the same item level to pull that much, so i see it as their reward for understanding their job much deeper than a DPS who parsed the same does. There are other things to take into consideration as well, however, what content you're doing being being a better example.
Self healing, more DPS, and stronger group utility aside, another reason that so many tanks have gravitated towards strength is that no content in this game right now warrants more than 18k HP, as well as constant use of your tanking stance (this sounds a little off-topic in regards to our conversation, but see me through, here). Because of this, you could argue that because the lack of content present where in terms of group utility, DPS, and efficiency, you want a tank to be "tankier", is why you tend to see such a small margin between tank dps and damage-dealer dps. In order to pull the DPS that the Warrior in that group did, they would need to be in constant Deliverance, as well as burn through their defensive cooldowns in an offensive manner in order to accrue Abandon stacks. But now, go into a fight like Thordan EX, for example, which requires a tank to mitigate damage like hell, and the margin between Main tank DPS and damage-dealer DPS will be much bigger.
I'm talking about the average DPS that a damage dealer should be doing at their item level, not the average DPS of people who play this game. If you're comparing a player who knows how to play their job, they should be compared to other players who know how to play their job. Comparing a good player to ones that don't have their level of skill as a basis for judging one job against another would be inaccurate for these purposes.
As a sidenote, while parsing can let you see your numbers and compare yourself to the rest of the players of the group, please keep in mind that context in which they are used. Item levels have to be taken into account, as well as job composition. Was there a DRG to buff BRD and MCH DPS? Where there 2 MNKS? Was one of the MNKS keeping up DK so the other one could constantly use Bootshine? Was there a BRD to buff caster DPS? Was there an Astrologian? Who were they using The Balance on? Was there a WAR to keep up Storm's Eye so the NIN didn't have to use Dancing Edge. Was the fight easy enough for the tank to trade mitigation for DPS and group utility when appropriate? Taking that into account, I'm using that information to tell you what the average DPS of a damage dealer SHOULD be at that item level, I'm not going to go into FF logs and tell you that a BLM shouldn't be parsing less than 2k DPS when I look up a fight that greatly benefits stationary casting.
