Comment by dllthomas

Man pages improve discoverability. You only find --help contents if you already know which command you want. Man pages are searchable (with `man -k` or `apropos`).

This is most relevant when it's a tool that isn't going to be immediately obvious anyway (if I'm trying to figure out how to do XYZ on heroku, it's not unreasonable to expect me to look at the heroku program I installed), and especially when it's a tool that might be installed by default or installed and forgotten about.