I think he actually had a clearer vision of the requirements than you do. In web dev jargon land (and many jargon lands) "the database" means "the instance of Postgres" etc.

But fundamentally it just means "the base of data", the same way "a codebase" doesn't just mean a Git repository. "Downloading the database" just means there's a way to download all the data, and CSV is a reasonable export format. Don't get confused into thinking it means a way to download the Postgres data folder.