There is a historical reason why Microsoft choose 7 characters. LAN Manager required a password up to 14 characters. It would then split the password into two

There is a historical reason why Microsoft choose 7 characters. LAN Manager required a password up to 14 characters. It would then split the password into two 7 character parts and hash each independently. So there was no additional security offered by the algorithm for passwords over 7 characters. Today, LAN Manager passwords offer little protection as complete random tables are easily available. https://en.wikipedia.org/wiki/LAN_Manager https://en.wikipedia.org/wiki/LAN_Manager