Command Line and User Friendliness
Personally, I think that command line is the most flexible and at the same time most intuitive user interface paradigm we have invented so far. There is a large number of people who would not agree with this statement. There is this this notion that command line is a thing of the past, and modern software must have a GUI whether it makes sense or not. Somehow a large number of computer users got it in their heads that this is absolutely terrifying, ugly, and outdated.
But it is not. This is a modern shell in a modern operating system. I took that screen shot on my Kubuntu machine which is actually quite newbie friendly. If you need to launch an application, you just type in the name. If the application is not installed, the shell will give you a helpful suggestion which package you should download to get it.