Unfortunately, few people heed lessons from those like Deming. As a result, we’ve picked up a bad habit as we’ve journeyed from the industrial age through the information age: Quantitative data has been fetishized. As a result, many suggest that “what customers want” can and should be measured.
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.