It's a shame the app store isn't considered a system library :-/
If appstore was part of every app and the appstore license only covered the appstore part and not the whole app, then that would be an improvement.
But I think it would be easier just to not have apps covered under the appstore license, and only add such license to their own DRM. How effective the legal DRM would be in that case could be discussed, but it would likely identical to consoles and tivo which are both gplv2 compatible. It seems unnecessary when looking at other products with DRM to have a license that cover every program running on them.
Both versions of the GPL have an exception to their copyleft, commonly called the system library exception. If the GPL-incompatible libraries you want to use meet the criteria for a system library, then you don't have to do anything special to use them; the requirement to distribute source code for the whole program does not include those libraries, even if you distribute a linked executable containing them.
- https://www.gnu.org/licenses/gpl-faq.html#SystemLibraryExcep...