I think your sandwich analogy is spot on in the sense that I can also just ask a human "please make me a sandwich" without specifying anything, and (most) humans could proceed to do so without more details. There should be more options, and a good "default" mode for people who don't want to fiddle with them. To my knowledge this is why most wizards have basic configuration options and a "advanced" button to click for the detailed configuration, and I don't see why Firefox can't just have the same thing.