You may not like it, but the Horde ARE seen as the Bad Guys and the Alliance as Good Guys. That results in different expectations, and different standards do apply.
If you look at it more closely, there are exceptions and nuances to both......but there is a reason why the Alliance are lambasted for Taurajo whilst Southshore is forgotten.
The horde _WERE_ the bad guys up until WC3 when it was turned on its head. Anyone new to the game until Mop and possibly Cata would see it as Horde = group of outcasts/underdogs banding together with alliance being your typical "human and elves good guys". In MOP for sure I could see the horde being viewed in a negative light. Cata possibly too depending on what quests you did.
Also blizzard them selves dont state either side is good or bad.