VDH`s power actually comes from its new tier set, making you 2 core skills fire and then their whole offensive kit just synergizes perfectly. If you search it on simultation sites etc the 4 piece skyrockets the dmg, whilst dk is just some str increase, every now and then. I guess after bdk`s Sepulcher set being completely broken, devs are a bit scared on how much can dks scale.
People saying tank dps doesn't matter probably didn't have 0,1% wipes
Tank DPS does matter lol. There's very few scenarios when you're doing pinnacle content where you don't opt for 'defensive' setups. Most of those are literally in the form of M+, not actual mythic raiding. You reach a point when the scaling reaches such numbers where you may have to talent slightly differently or opt to use a tanking trinket that is generally never used. Generally the correct way to play for tanks in 99% of scenarios is to opt for as much damage as possible. Very few real world scenarios where you have to opt for 'defense' in the game, whether that be through enchants (lol), or the talent tree.For Mythic raiding? Not really. You have so many tools to bypass survivability checks and most of that literally just comes down to playing your class properly.Mythic + is probably the only form of content that is challenging to tanks simply because you're doing all the jobs that a DPS does in addition to facing mobs and setting the cadence of the group.The biggest issue with DKs is that the talent tree is pretty garbage by comparison. 35-45% of your damage comes from procs outside of aura effects while the other ~12% comes from auto attacks. You don't get chunky meaty hits with any of the baseline abilities as a DK as opposed to most other tanks in the game. I haven't kept complete track of it, but Blood DK has had it's baseline aura effect buffed over half a dozen times since the expansion launched (which is a lot), and it still does awful damage in raids. As you can clearly see when baseline aura effects are applied like that (and 6.5 and 8% damage seem like a lot), it's only really buffing the damage of the class by 40-50% max.A lot of people view tanking completely wrong or believe in things that happened so many expansions ago without realizing that's long past. Yes there was a time where some tanks required more attention than others, but they also took a massive amount less damage as well. This hasn't been the case for awhile now, and it's certainly not how tanks play at the moment. In nearly every scenario tanks are responsible for their own well being and the myth that some tanks can just live forever and therefore should be punished damage wise is just rubbish.DKs certainly aren't the 'magic' tank or self sustaining tank like they use to be. The only thing that makes them good on raid encounters is encounters where you can completely cheese push mechanics with death's advance, and the rare occasion that encounters benefit greatly by having abomination limb or gorefiends (gorefiends being a talent, and abomination limb being something DPS can pick up). So why take them when the damage they provide is arguably worse, they bring zero buffs to a group/raid (that others can't provide), and those above two scenarios that the community thinks DK tanks historically are, aren't even necessarily true? You don't.
Despite being in the bottom of dps, list BDK is 2nd popular tank losing only to FoM paladin. Bears got 2nd place, but losing more then 3 times in numbers. The point is, BDK got nice utility and cheese mechanics second only to pally sometimes, and arguably easiest and fun to play. You simply cant get best things(aka DPS) on easy mod, otherwise 95% tanks will play BDK and it will be disaster. Blizzard trying to control population in a way