Why does the "@" erase the full input line when accessing a Serial connection via agetty?

Issue

• use of "@" character in a password
• The "@" character can be become the "Kill" (erase full input line) character for the Console/serial connection.
• This prevents its usage in any password of users/logins which can log-on to the Console/serial connection.
• This behavior seems to be a special/particular one of the "agetty" command which is by default configured to handle/receive Console/Serial connections, so why not switch to "mgetty" which seems to do the job?