Originally Posted by
Leodok
...Except for monks! EVERYONE loves the idea and decides to follow this new religion from a distant part of the world, which they just found out about.
And this is the only actual reason. They wanted to give everyone monks, but explaining it in any decent way would be too much work, apparently.
Rather that telling us of a group of night elf druids learning of the Celestials and seeking them or some tauren re-discovering their Yaungol kin and starting to follow Niuzao, they did... nothing. Just gave everyone monks for the sake of it and left 10 race-class combinations making no sense at all.