OS X Backup doesn't do other users folders

I don't recall anyone every mentioning this:

.Mac: Backup intended for backing up files in your Home folder, but not your entire startup disk

...Files in other user's Home folders Because Backup runs with the same file permissions as the currently logged-in user, you can't use it for backup up files in other user account's Home folders even if they are on the same computer. Log in as the other user before using Backup.

Backup works with .Mac. In some ways it's the precursor to Time Machine.

I wonder how many people think they're backing up the family's files, when they're only backing up their own ....

Kind of worthless on a multi-user machine.