TL;DR: The affixes are insane, some mobs make them practically impossible to do, and they’re just not fun.
I’d usually reroll normal affixes like drifting shade and storm vane’s wrath because they’re just not fun in a “normal” nightmare dungeon. But having them in vaults is beyond a joke.
Having mobs that teleport you around a map when your progression is actively punished for standing in the wrong spot is also super-painful.
The kicker though is the pacing. Traps are bad enough in RPGs where you aren’t harshly punished for stepping on the odd one here or there. I can get through one of these and open all the chests, but only if I second guess every single movement to get the timing right. It totally breaks the flow of the game.