When we first got the personal computer, we didn’t worry much about how things worked. We were, frankly, stunned that we even had such a thing. You had to learn some arcane lingo to type into a DOS prompt. That the computer might be difficult or awkward to use didn’t occur to us. But things gradually got more sophisticated, and when the original Macintosh came out with its powerful graphical user interface, we started realizing that the process of interacting with a computer could matter to us.
Software developers started having to think not only about how the program was going to get the job done, but also about how the user was going to interact with the program to get the job done. It became clear that a good user interface was something that would sell more software. If it were easy and intuitive to interact with an application, then users could get more done and would love the application.