So this is tangentially related by why do people seem to push Vi? Nano is a perfectly serviceable editor. If I need to do extensive editing I always end up loading it into Atom, Sublime or some other editor anyway.
I've never really had to use a console editor for more than 10s of lines.
Nano is fine for 10s of lines, but Vim is great for much much more than that. It's also nice to have the same keybindings for every console app (gosh I love readline), and it's repeat commands make editing text an absolute breeze. Why open another editor on my host if I can edit the file in my console on a remote server?
vi keybindings are ubiquitous, so familiarity with the editor is beneficial outside the editor. Just offhand, both ncdu and tig (which I have used in the past hour) respond to vi keystrokes.
It's not as hard as it first seems to learn, either. Well worth the time spent, vi is worlds more powerful than nano.
Nano is not as ubiquitous as vi. Every single *nix box will have vi on it, so even if you prefer something else, it's still in your best interest to learn the basics of vi.
I find it a bit irksome that when discussing command line editors, the dichotomy appears to be be "nano vs vim".
There are other CLI editors. I'm quite partial to ne (the Nice Editor), which has more manageable shortcuts than emacs, a command line (it's still a non-modal editor, to be clear), macros and syntax highlighting.
Also jed is not bad. While vim (and nvim) have advantages, and certainly benefit from being ubiquitous and having ther shortcuts replicated in other programs, users should shop around, even on the command line.
Also, the original comment was on "console editors" and not on "command line editing", which is what I thought the subject was about. Looks like I struck out on the whole comment.
I've never really had to use a console editor for more than 10s of lines.