User blog comment:Godisme/A Piggy Party/@comment-5551986-20121220003541/@comment-2048489-20121225140319

Well they did have the asauchi, right? They said they were GIVEN to people without the capacity to learn their own Zanpakuto's names. Maybe the idea of Zanpakuto release from within was actually invented fairly recently, and up to that point they always used mass-produced swords like we use mass-produced guns :P