Gnome File and Finder both have such issue. Gnome file manager at least provide ctrl + L.
This will copy either the directory (if no selection) or the selected file(s).
If you enable the path bar, I believe this is also a copyable element.
Finally, dropping a file or directory into a plain text control that cannot take file or folder references (like this HN comment box) will fall back to the path name.
The Finder has an equivalent with Command-Shift-G, and if that key shortcut is too cumbersome it (along with all other Mac menu items) can be re-bound in System Preferences under the Keyboard prefpane.
Most of the things mentioned in this comment chain are easily discoverable in the Finder's menus… it really pays to peruse menus in Mac apps when searching for a function.
If the path bar is showing a folder, you can right click it and select "Open in terminal".
The resulting path input modal even supports tab completion.