The difference here is 2.0 vs 3.0 and optimal role in a raid. Both of which I don't think you're taking into consideration when using this an a basis of rebuttal.
You can't really base what we are going to get
completely off of what we had in the past. All tanks were given abilities that allow them to DPS more efficiently in HW. Yoshi said that when they originally designed raids for 2.0 they never expected our community to have so much healer DPS being pumped out. So guess what? Now our encounters will be tuned for tank/healer DPS. From 50-60 a DRK gets 3
purely DPS moves with no enmity attached to them, 1 enmity AoE/self-heal with dark arts and 1 legit self heal/refresh buff that works best when dealing with multiple mobs and useless against a boss with no adds. Our DPS line-up basically doubles in effectiveness going from 50 to 60 and our tanking ability stays largely the same.
I am an ex-DPS from 2.0, but I leveled everything to 50 and tanked up to t12 so I do understand what it takes to be a viable tank. I also understand what people are going to want and expect out of the roles they bring into a raid. Now, with the Dark Arts dupe being fixed, any spot we may have had as an OT that can contribute legit DPS for longer than a few minutes was dealt a harsh blow. Who is going to seriously bring in two paladins to a progressive raid? Are you willing to hang around until enough people have beaten the raid with an optimal party and they feel like messing around to pull in a WAR to MT? WAR is in a good place from what my buddy is telling me so I don't know firsthand of their viability as an MT in HW, but I know I never saw any groups opting to use a Warrior to MT turn 13. Why, when a paladin is better?
We already get to deal with this conundrum just
being a Dark Knight, because many progression groups are going to ask that same question. "Why should I bring you as my MT/OT when I could find a PLD/WAR instead?" Unless you are good enough to prove with your skill that you can mitigate properly and help healers, or DPS enough to contribute acceptable numbers....or have some friends who don't care either way I feel like it will be niche groups and a tough sell for any random composition to settle on a DRK.
In 2.0 if you ran out of TP as a tank it didn't really matter. We could afford for you to just sit there and auto-attack while you regained naturally, even on OT because that DPS was never needed. Raid encounters weren't designed with your DPS in mind. They will be now. That's why people were able to sell FCoB carries pre-echo, other roles that weren't intended to contribute 300+ DPS possibilities (looking at you scholars) and tanks that could potentially hit what a Bard brings to the raid DPS-wise were crushing SE expectations. It's very clear that DRK was designed to be viable in both roles (MT/OT), just as AST was designed to be a really strong complimentary healer to whichever other healer they were paired with. No one knows who designed Machinist because they were shot instantly after
Paladins will never crush 900-1000+ DPS as an OT, like WARs are doing. And WARs can do that for 3mins without even needing to use their TP skill. My TP was completely gone in 3mins. Good DRKs were close to that before Dark Arts was fixed, but will now probably be a good 200+ DPS behind a WAR. I'm curious to what an OT PLD can do, but from leveling it in the past and knowing what skills they get from 52-60 I don't see them being better than a DRK.
Anyway...that's not really what the TP concern for me is about. Like you stated below this quote, Paladin is king of mitigation. I don't want that title on DRK. Warrior is the king of burst, I don't want that title either. We play and feel like a middle-of-the-pack tank that, with enough skill, can perform both roles sufficiently enough to be viable. Our insane burst was nerfed, so now we have above average-to-good sustain DPS. We have enough defensive CD's to weave that we can stay at least protected from anything that would require mitigation. I think we are viable as an end-game MT for a skilled player. I think we need some kind of tool for TP if we are going to be viable in a DPS/Tank role for anything longer than 2-3min periods of time.
Let's just use Turn 8 as an example. If SE drops a "turn" of Alexander that stays in the same vein as that fight, a 2nd tank
won't even be brought unless they can contribute high numbers. Serious players running parsers are going to see the complete bottoming-out on the timeline graph for 20-30 seconds after 3mins of DPS on DRK and we will be largely omitted from that content unless we are designated MT, or that the DPS we can contribute is good enough for us to take the hit and still contribute to the win. And if a raid comp consists of PLD/DRK, the DRK is obviously not going to take the MT position away from the PLD and I don't feel like "go out and level a warrior" is a valid reaction to what will almost definitely happen. Maybe not for Normal Alex, but absolutely for Savage Alex.
I was a career Bard for 2.0. We went from being the hottest thing since melted butter and the only thing taken into endgame, to being a necessity to raids only during progression, to whatever this shitstorm SE created for us in 3.0. I've watched all kinds of jobs get left behind in content if they didn't level something better to help the group. I love playing DRK, it's the most fun I've ever had with a job in this game. I can deal with being the average tank, because I'm positive I can play it above average. Some type of TP management skill would even it out and at least allow us to perform well in both areas, but not better than the other tanks when played with equal skill.
Just my 20 gil. I talk to much for it to be 2
tl;dr: DRK is the average tank with some very flashy moves and an extremely unique skillset that contributes to how fun it is to play. There is a ton of weaving and micro-management involved in playing the job optimally, but there is nothing fun about being relegated to auto-attacks and spamming one MP move (if you even have MP left) while waiting for TP to regen when you are supposed to be helping DPS. Currently a DRK's viability in a high difficulty endgame setting as an MT is just fine, but it needs some kind of TP management move to allow it's viability as an OT to be the same.