> Then we have to boycott Hearthstone. While the current case is neither surprising nor substantially important, it is important because of principle.

Boycott the Hearthstone pro players/streamers.

Blizzard won't notice the money from a couple hundred people going away. The streamers/pros on the other hand will most certainly notice even a couple of people going away and will leave Hearthstone to rot.

Once the pros leave Hearthstone for another game, Hearthstone will die. THAT will get Blizzard's attention.