-Before you give up on DRK entirely, keep in mind that the majority of tank busters in the game (and especially in HW) are magical, making Dark Mind pretty great.
-TBN becomes better and better as %dmg reductions get stacked up. The opposite is true for Sheltron and Inner Beast.
-Popping TBN results in negligible (almost invisible) loss to dps, or it is a gain if used to pop delirium at the start of a fight.
-TBN is not gated behind gauge, and can be used outside grit. Sheltron is gated behind auto-attacks or blocks, and Inner Beast can only be used in Defiance.
-It's true DRK has a weakness for having over simplified rotation and over-spammy oGCDs, as well as a hectic opener as you try not to waste MP or blood generation.
---etc etc. The list goes on. DRK is the selfish tank, nearly invincible if played right, does not need or desire to use Living Dead to tank very well. Unlike Paladins, who need to use Hallowed, or Warriors who are straight paper tanks.
Here's a list of tank busters that DRK is great (miles ahead of PLD and WAR) for mitigating.
-01S: Twinbolt.
-02S: Evilsphere
-04S: Thunder III, and on Neo, Aero III
-05S: Doom Strike
-06S: Demonic Shear, Last Kiss, Actually just everything its ALL MAGIC.
-08S: Hyperdrive, Wings of Destruction.
-Lakshmi: Pull of Light
-Shinryu: Akh Morn
-Byakko: Heavenly Strike
So with the exception of 3 fights, DRK outperforms in self-mitigation by a long shot. On those 3 fights, DRK performs equally.
DRK is on par with PLD on dps. Can beat WAR if good luck on Bloodspiller.
TLDR; DRK is more punishing because MP can get out of hand if you're not practiced with it. Otherwise, DRK is great, effective, and flashy. This post recognizes that DRK has sucky abilities, but that's because everything else is so disgustingly strong it would be unfair to buff Living Dead, Sole Survivor, Dark Passenger, or Quietus.