Focusing on the core business is what differentiates real product design from interface design or even user experience design. Fundamental product design is really hard and requires a lot of legwork, but this is what designers at the highest level do — and it’s why their work is better than yours.
If this is so self-evident, why do Jared and I press the point? I keep beating the drum because I want designers to change the way they think about their role and become better stewards of good design.
You see, I mostly write interface text for apps and websites. It’s a style of writing where brevity beats brilliance, and every character counts. Writing interface text is actually a lot like design—designing words for people who hate to read.