The Order Halls were established when the Horde and Alliance were fighting during Legion, the Order Halls were made to be above that pettiness.
But then Azeroth started bleeding diamonds all over the place which caused Horde to burn the Alliance's favorite tree and the Alliance to attack the Horde's sewer city.
That's why we can't have nice things.
"It's not what we don't know that gets us into trouble; it's what we know for sure that just ain't so." ~ Mark Twain "The time you enjoy wasting is not wasted time" ~ Jesus of Nazareth "把它放在我的屁股,爸爸" ~ Dalai Lama
But then Azeroth started bleeding diamonds all over the place which caused Horde to burn the Alliance's favorite tree and the Alliance to attack the Horde's sewer city.