What you are saying doesn't help when automating things, unless you want to make a macro that controls the mouse and keyboard? That'd be risky. GUIs are great for discovering features. So great in fact that the API ("user interface") often changes, if only by a bit. Terrible if you are in this for the long run, or want to automate things.
I don't really want this to be a command-line vs GUi thread, but you kind of started it (even if a bit off-topic).
> but using Shift+Enter to get a newline is fairly common and easy to try and guess.
How on Earth is that intuitive? User interfaces (coomand line, GUI, web, voice) typically rely on common patterns (desktop metaphor, doule click, right click, alt+letter, F1, ctrl+c, etc) being memorized by their users.
At least, command line interfaces have the merit of often being documented (that feature is documented line 91 of my offline `man git commit`). I had overlooked that bit, but had I needed it, that would have been pretty easy to find. Most GUI software do not even pretend to have documentation anymore (KDE is still pretty good at this).
command-line vs GUI is a choice. I work most often with the former as I've grown comfortable with its patterns over time, after seeing it a lot. An added benefit is that I can often re-purpose the knowledge I learn for writing scripts. But not everyone necessarily needs to do so. And I think that picking the same tool for every task is pretty dumb. I like GUIs a lot for stuff I'm not familiar with, or don't do often.