Hearthpwn

Card draw is totally not imbalance. Card draw, is mainly related to class mobility in Warcraft. If you see, the better card draws are owned by Demon Hunter, Rogue and Druid (see feral). These are indeed the best 3 classes in Warcraft for mobility. Sometimes card draw is also totally referred to this, Sprint for example. So the developers wanted to add a flavour in the game remembering class mobility. When you are drawing cards, it seems like when you are boosting your speed. The worst card draw are owned by classes that are indeed stones in class mobility, see priest, paladin and shaman. 

So, card draw is not imbalance is part of class identity. Like classes have not singol target removal, heal, taunts or mass removals, others have no card draw. Class identity man, I don't think that this will change. Priest, Pala and Shaman will always have the worst card draws. 

Hunter by the way, is good in class mobility but not so good in card draw, so I think that in time he will receive more card draws, I am pretty sure that one day he will receive a card called "disengage" in order to draw. Mage probably will receive one day "Blink" in order to draw. It is part of these classes flavour.