Nano is extremely valuable for people learning the system. Typical alternatives are vi and emacs, which are extremely opaque, to the point that it's not even obvious how to exit them. UNIX tutorials will often say "use control-C to kill a command" and then that doesn't even work for this!

Nano tells you how to use it right on the screen. Control-C still doesn't work, but it tells you how to exit. Saving files, paging, cut and paste commands are all shown. There's easily accessible help!

If you're learning UNIX then editing files is handy. Without nano, you'd have to spend a bunch of time learning how to use a text editor before you could do anything that needs text editing.