I always say you don’t need to use the command line to use Linux effectively—I know many Linux users who never crack open a terminal window and are quite happy. However, even though I don’t consider myself a techie, I spend about 20% of my computing time at the command line, manipulating files, processing text, and using utilities.
One thing I often do in a terminal window is viewing files, whether text or word processor files. Sometimes it’s just easier to use a command line utility than to fire up a text editor or a word processor.