The following are considered as the reasons why such a situation was generated: One is that the literacy rate of the people at that time was low, and another is that, being made privately, they were made irresponsibly.
これらの原因には、当時の人々の識字率が低かったことや、私的に鋳造されたためいい加減に作られていたことなどが挙げられる。