There was not a fully fledged faction war since WC2, it began against in Cataclysm, prior to that it was an uneasy ceasefire with random skirmishes and conflicts.
The main storyline of Pandaria was the faction war post 5.0 and it's a massive part of the Wrathion storyline (uniting Azeroth under 1 banner), so to say it's not a faction war just because you don't like the way it's written/played out is just childish.