Kuhn: Copyleft Won't Solve All Problems, Just Some of Them

It is intended as an admonition to courts, if for example someone gets charged with criminal copyright infringement for trying to circumvent your GPL'd DRM. You're not a party to that case, and arguably the license doesn't have any direct application as a result, but the defendant can use this clause to show that your intent was not to effectively control access to the copyrighted work, and therefore it doesn't count as DRM within the definition in the statute.

Whether a court buys that argument is another matter, of course.