Earlier quoted context omitted.
I would argue that small command-line tools "the unix way" combined with a competently written -h help page is quite discoverable. Maybe not for a general computer newbie, but certainly for people used to /other/ cli tools.
This only seems to work in practise for tools that are very small, otherwise exceptional writing is required (which, by definition, will rarely occur). I can't imagine (to pick a particularly extreme example) that anyone has ever learned to use git by reading the man pages. In contrast, even features in pretty poor GUI apps are by default generally discoverable.
If you can’t spend time on one of your main tools docs to grasp what “merge -r 403:480 -c -473 ^/branches/rt0” does and how to command it, then sit there and code, folks will do maintenance for you.