Welcome! Actually, you were dealing with 2 slightly different things.
First, "Good" is the reading by our password strength meter. It's intended to help members select passwords that are difficult to crack. See: Forum Software Updated: Show Password Strength
Second, the minimum password length is 9 characters. Most people expect 8, so we go 1 more. The forum software will accept a maximum password length of 100 characters.
To some, the glass is half full. To others, the glass is half empty. To an engineer, it's twice the size it needs to be.