Horde bias is not just "giving Horde interesting storylines" it's about shouting "For the Horde!" at Blizzcon, and making people feel like the Alliance is a boring side that no one 'cool' plays. It's about not doing anything when Horde starts to dominate population numbers. It's about building a statue of an orc at Blizzard HQ.
But I remember this: those people shouting "FOR THE HORDE" enabled sexual abuse, so I get to have a sense of moral superiority with war mode on.