THIS ALL OF THIS.
As a prime example, I’m a DK main. Blood tanking is a ghost of its former self. Is it still viable and does it work, sure it does. However to me at least it’s not nearly as fun as it was in Pandaria as a prime example. There’s some modern aspects of blood DKs I like and DKs as a whole, but alot that I don’t. I could go into gritty detail but that’s another can of worms.
Biggest reason I often dread tanking for pugs is the amount of pure jerkish sweatlords you run into that take it WAYYYY too seriously. You’re either speced wrong according to them, not tanking in the right spot, pulling too much, pulling to little, pulling just the right amount but spilled the porage on the way, their friend does it differently than you and he’s better, or a host of other reasons to justify their jerkish behavior. Anymore if they start running their mouths I just offer to go frost spec and let them tank it if they think they can do better. If the run goes smoother then great. Far too many want the benefits of having good tanks, but none of the responsibility of not being a tool that comes with it.