> I always assumed there was more to Org mode than "Markdown for Emacs", but this post makes it sound exactly like that.

That is because the post focuses on org-mode: the markup language. But there is also org-mode: the agenda tracker, org-mode: the literate programming system, org-mode: the spreadsheet, org-mode: the website publishing system, org-mode: the document writing system, org-mode the time-tracking system, org-mode: the personal wiki, etc.