It is the user’s choice. If the password is not saved at the login screen, scheduled backup already set will run, as will LiveProtect. The option to save the password allows all users that access the workstation where the client software is installed to change backup settings. For e.g., an account set up on a server, should usually be accessed only by the systems administration and thus this option would not be checked in this scenario.  It's really your choice, and how strict you want security to be on that workstation or server.