The number one reason to write CLI apps in node is npm. npm gets package management right, preferring local dependencies to global ones - this means no worrying about what version of a library a user has in their global environment.
You also get to bring node's parallel io-centric patterns to your scripting. Need to download a bunch of files from a remote host, process them, and write them to disk? Go for it.
But take it with a grain of salt: it's very much a use-what-you-know kind of thing.