This is absolutely not the case. There is a difference between UI built for people with no training/experience, and those with some training/experience; see e.g

This is absolutely not the case. There is a difference between UI built for people with no training/experience, and those with some training/experience; see e.g. the Therac disaster for an illustration of the UI challenges of building for experienced users. On personal computers, it means attention to keyboard shortcut design, making data more prominent and well-separated visually, and labels less prominent/space-consuming. Consumer-oriented UI is not the only UI! Users' time and commitment are not unlimited, but they are substantial when e.g. you are in the military and already need to be trained to understand the problem domain. EDIT: A great example is the UI of the controls of a car. It's important to put commonly-used controls in ergonomic areas, follow the principle of least surprise, etc.; but it can still be built with the assumption that the user is a licensed driver and knows where the turn signal usually is, that up is left and down is right, what all the assorted symbolic labels mean, etc.