Earlier quoted context omitted.
I define it as a casual user of my libraries. Designers are the best example: they're usually hooked into the development world and would be interested in a clever command line tool, but they normally don't have an entire build chain under their belt.
In my neck of the woods, a designer's tool chain rarely extends to anything outside Adobe tools. That's what developers are for ;)
I think that's the main argument. Getting started with command-line tools and developer-type stuff should be as easy as possible, so that people can try new things and break stereotypes and do more than they thought they could do.