Originally Posted by
Coconut
It's because not all Allied Races are or will be sub races. Yes, you can call Dark Irons a Dwarf sub race, but you can't call Void Elves a Night Elf sub races or Nightborne a Blood Elf sub race, which throws your menu out the window. If later on they decide to add stuff like Vulpera, well, that's not related to any of the existing races, so how would it work?
Imho the rep grinding part, while unsavory, is a much smaller time sink than leveling all the alts resulting from a high influx of appealing races. With Wildhammer they can just add a new customization option to dwarves called Tattoos and a regular dwarf can become a Wildhammer. Isn't it implied that dwarf shamans are Wildhammer to begin with?