The thing is that it doesn't even make sense with Viera. We just have ears coming out the top of our heads, absolutely nothing preventing the all the existing hairstyles in the game from being used, with perhaps the sole exception being the afro.
While I do agree that Hrothgar should have more options than they do, their heads are a completely different shape from all the rest and their hairstyles are clearly designed directly around the different face (which are really "head") options. You can't just throw on one of the existing hairstyles on them, but you absolutely could for Viera.
