I agree that it could be a separate license, but that doesn't really contradict the point that GPLv2 was intended to prevent DRM scenarios that in practice violate basic idea of being able to run the changes. It's a natural thing to want, even if Linus doesn't find it important.
In practice though authors of GPLv3 see it as a clarification of GPLv2, i.e. they should have the same practical intent.