Nano isn't even that simple. Ctrl+X to quit? I guess if you use phonetic sounds to figure out how to exit a program. At least Vim uses the idea of "use what the words start with."
I personally use micro in the terminal, and Kate if I want a GUI to write. Vim and Emacs are fine for those who want it, I have no stakes in the editor wars beyond "I just want my program to do what I want, and I want it to be simple to learn."
Meanwhile I can just use the same shortcuts every other program made in the last 40 years uses. Ctrl+Q to quit, Ctrl+S to save, Ctrl+Z for undo. If I wanted to consult a cheatsheet to relearn keyboard shortcuts, I'll use vim and emacs.
To be fair, you can easily rebind all the keys to be more normal by adding a .nanorc. Though, Ctrl-Z conflicts with suspend in many terminals, so I keep that one as Ctrl-U. A .nanorc also allows turning on mouse support, changing the color scheme, etc.