This is something I always keep harping on about: Simplicity and the ability of something to explain itself (=be intuitive) is a positive quality in many domain

This is something I always keep harping on about: Simplicity and the ability of something to explain itself (=be intuitive) is a positive quality in many domains. But since the iPhone got popular people try to use that UI paradigm everywhere, regardless of the downsides. A cash register software needs to be fast to learn AND fast to use. But the latter is more important than the former. Some phone app that is used once a week by your grandpa needs to be easy to use first of all. The software used by a flight traffic controller needs avoid mistakes first, be fast to use second and easy to learn last. So it is important to figure out who is going to use your software and what their priorities are (or should be). Very important note: Like there are solutions that are powerful and intuitive to learn, there are also solutions that are neither. You don't always have to trade one for the other. E.g. a text editor like vim totally traded the ease of getting into it for the power after. If someone were to make a similar editor today they could however easily create an editor that is intuitive to use by the beginner and allows similar powerful editing for the poweruser at the same time. Software that is intuitive first usually has no depth. There is no additional, more powerful layer you can discover. And often this is an active decision. Often it is also a bad decision.