In some situations, it may be desirable to present notebooks without the code. This is easy to do and can be controlled from within the notebook metadata.
To hide all input cells of a notebook, add "hide_input": true to the notebook metadata.
It is also possible to hide the code of select notebook cells by adding "hide_input": true to the notebook cell metadata. https://jupyter-contrib-nbextensions.readthedocs.io/en/latest/nbextensions/hide_input/readme.html
One case where this behavior can be useful is when developing a dashboard or report in a notebook and using papermill to execute the notebook. In this case, the --report-mode flag in the papermill command-line interface will also hide code cells in the run notebook. https://papermill.readthedocs.io/en/latest/usage-cli.html