Design involves both technological engineering and psychological engineering, and psychological engineering is harder. Doors don’t often fall off their hinges, get stuck, or snap in half—all feats of technological engineering. They do often lock accidentally, set off unintended alarms, and mislead people about how to open them—all failures of psychological engineering.
[…]
Once spotted, psychological engineering problems are tricky to solve. Unlike battery life or fire resistance, “intuitiveness" is hard to quantify and thus hard to optimize. The fundamental attribution error leads us to blame design failures on stupid people rather than stupid products.
[…]
Anyone who can overcome these challenges is rewarded with indifference. Psychological engineering problems are hard to spot in the first place, so people rarely notice when you solve them. People hate pushing a pull door, but they don’t think at all when they push a push door. Unlike technological engineering, which can be explained and sold (“This car gets 55 miles to the gallon!”) and thus copied and improved, good psychological engineering melts into the background.
The good designs that don’t spread, then, are probably solving psychological engineering problems. Technological engineering marches ever forward, which is why the next phone you get will be slimmer and faster and last longer on a single charge. Psychological engineering remains stuck, which is why the next building you enter will probably be full of Norman Doors.