So leveling DRK at post 70 as a WAR let me completely understand alot of DRKs frustrations.
Yes, DRK just became another WAR. Its disappointing their identity got tied to another job (which has its own problems of being 80% boring during its rotation) when they should have thier own identity.

Second the resource requirement for TBN now feels clunky. When playing PLD you don't use your resources for anything BUT defense which makes it fine to be tied to a resource. For DRK it doesn't feel good holding having to manage your resource to make sure you have your identity defensive cooldown ready while all other tanks don't have this issue.

Then there is Living Dead. Lets be real, its the worst tank invuln by far. The healing vaccum that it is isn't something any healer likes.

"Well just Bene it!" Isn't a good argument. In order for a DRK to be viable or even considered used then it would mean you have to also force another healer to go WHM. What if your healers don't like WHM? Then you get to the problem that if you don't have a WHM its a resource dump they have to into "panic mode" to heal you up to full. Even WAR with the fact its invuln doesn't mitigate damage is still better because they don't have to heal you to full in 5 sec. They just heal you enough to survive the follow up attacks before topping you off.