The 10-character minimum for passwords is unusual and makes the process of password selection for this site different from other sites. It would be a big help in remembering what password I used if special rules like this were displayed on the login page.
I remember I was puzzled when registering because of my login name (I was trying to use a space) and I spent at least half an hour before understanding this point of the rule.
I assume it can be worse when being refused one's password.
I side with this demand.