One thing that Warlock can be good for is digging for the more overpowered treasures. I took a Warlock deck with 2 very mediocre passive treasures to 9 wins (losing to double deathrattle passive Hunter decks) simply because I had Wax Rager in my deck and the ability to dig for it with the draw Hero Power (and a good amount of discard mechanics like Egg/Silverware Golem/Hand of Guldan).
One thing that Warlock can be good for is digging for the more overpowered treasures. I took a Warlock deck with 2 very mediocre passive treasures to 9 wins (losing to double deathrattle passive Hunter decks) simply because I had Wax Rager in my deck and the ability to dig for it with the draw Hero Power (and a good amount of discard mechanics like Egg/Silverware Golem/Hand of Guldan).