Originally Posted by Lore
Warlords of Draenor’s story is about the people of Azeroth (namely, the Alliance and the Horde) venturing into an unknown world and building up a force strong enough to take out an enemy stronger than anything they’ve encountered before, on that enemy’s own turf. While there are certainly some alliances to be made along the way, and those are definitely major parts of the story, the core theme is about you and your faction fighting for survival.
So, as development continued, we came to the realization that it just doesn’t make sense for the Horde and Alliance to spend so much energy and resources building up a stronghold on Draenor, only to base their efforts out of someone else’s city. We’re not helping the Draenei or Frostwolves fight off the Iron Horde – they’re helping us. The Alliance and Horde both have major bases of operation on Draenor. That should be where they’re working from.