I'll use a GUI all day long, but there are some things a GUI isn't and scriptable is one of those things that it isn't. I'll even admit that I've come across a device with a scripting system but no CLI. Even then, it was still missing something valueable... Output and the ability to parse the output as part of the script.
Actually, I think Rharland2012 said it better... "When those things aren't necessary, a well-crafted GUI is the perfect tool in the box"