>**Answer**: Because most operating systems [HASH][1] passwords once entered (and store them in a database).  This means that the entire password **is converted into a collection of cryptographic hashes, random-looking strings of characters into which the passwords have been mathematically transformed to prevent them from being misused**. 

>**So**: One a password is HASHed there is no way to attack each character.  That is circular logic.  *To attack each character you must know each character*.  *To know each character you must attack each character*.


  [1]: https://www.wired.com/2016/06/hacker-lexicon-password-hashing/