Blizzard Favors Aliiance?

I've seen a couple threads where Alliance have claimed that Blizzard prefers horde, yet there has been an episode of South Park made using the Alliance and the World of Warcraft movie is going to be Alliance based. So does Blizzard really prefer horde? Far from it in my opinion. Sure we get a big fortress in Borean Tundra, but it's only a stairway and like three rooms.