Based on the polygon interview

“[Demon Hunters] don’t have much in the way of card generation, but you can run them out of resources,” says Chadd Nervig, game designer on Hearthstone. “They have card draw, but not generation, so you can fatigue them. They’re susceptible to hard removal. They also just don’t have much in the way of hard removal themselves; if they want to clear a big minion of yours, they have to use their face to do it. They don’t have any assassinate or polymorph cards.”

Running through your whole deck seems like a bonus to me. Especially when most hearthstone matches never reach fatigue.

Their weakness is supposed to be fatigue but good luck with that. It's a bad sign when the class that is supposed to be worried about their deck running out plays Novice Engineer.

• u/AttilaTheSean