I'm mostly trying to fill a niche for Time Machine users on a laptop who don't own a Time Capsule.
If you don't have an external hard drive plugged in and Time Machine fails a backup, the menu item says "Latest Backup: Delayed." If you open the System Preferences, it simply says "Failed."
This is more useful for me and it helps me to decide when I want to connect to my external drive.
(Version 1.5)