You are missing the point. JA and many others sell proprietary, commercial, copyrighted non-GNU/GPL *products* (not services), such as templates and add-on extensions–some of which are embedded into templates.
Joomla.org:
In our opinion, templates are composite packages that consist of both code elements and non-code elements. We believe that the code elements of a template must be licensed under the GNU GPL because they are derivative works. However, the non-code elements are just data acted upon by the software and may be licensed in any way the author sees fit. The non-code elements include elements like Images, Movies, Animations, CSS and formatting markup.
where is this being discussed in JA forum? I did not find anything in the search.