Nanamo Ul Nanamo is easily the most adorable little lady in Eorzea. Every time she shows up in a cutscene, my poor Lalafell has to fight her instincts not to give her a big hug...

And that's why we shouldn't be able to copy her appearance.

She's special because of that uniqueness. Her outfit, her hairstyle, her makeup. All of it combined makes her different to other Lalafell, and is the sole reason we consider her so cute. If you make it available to all, eventually there are tens, maybe even hundreds of Nanamo's all running around which takes the special uniqueness out of her character.

Of course, more of that Halloween candy would be nice so at least we can play pretend for a while.