The problem is decks that are pretty good aren't good enough. They used to be. But win conditions are so polarizing in hearthstone that you can't just play good cards with reasonable synergy.

Yesterday I was playing against a pirate warrior who had set my life total to one by the end of his third turn. I was going first. When that type of power can exist, you don't have time to play 1 mana 1/1's, let alone 3 mana 1/1.

Decks swing in power too hard by draw order in hearthstone at the moment.