Well, Jaq, the thing is that if the raid on Garrosh turns out like this, then yes, Alliance is only there to advance the Horde's story:

We see THRALL, standing before a determined looking group of Tauren Braves, Troll headhunters and Orcen Blademasters. The demonic fires of Orgrimmar, a city corrupted by the newly ascended Dread Lord GARROSH HELLSCREAM, smoulder in the distance. Small bolts of lightning crack through the air around the DOOMHAMMER as THRALL begins to speak:

THRALL: Today, every Tauren, every Troll, every Elf, every Goblin and every Orc stands united against demonic corruption. Against the mistakes that darkened our past. Today we take back our city! Reclaim our destiny! Restore honour and pride to the Horde!

For a brighter future, warriors of the Horde! Loktar Ogar!

Lots of banging of weapons against shields, we see Orcs next to Elves, Tauren next Trolls, a united Horde.
In the meanwhile, THRALL wanders off to the side and the camera pans over to a group of Alliance soldiers, battle-ready, assembled behind HIGH KING VARIAN.

THRALL, in a conversational tone: Also Varian, we're going to need you to create diversion. Why don't you go over there and bang at the front gate? Okay? That'd be great. Thanks!


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If it turns out anything like this (and right now, I can't see any reason, why the Alliance would help to install Thrall, or any other warchief that is not a patsy for the Alliance), then that means that the Alliance is only a tool, and in the end a dispensable tool, needed to propel the Horde storyline forward.

You can complain about 'QQ' all you want, but don't act like there isn't a legitimate point to be made, relating to to the way Blizzard has handled Alliance story advancement so far.