It's not so hard to explain why people would fail to understand the significance of this. To understand it requires the combination of (i) a grasp of the issue (including the ability to understand that in certain contexts, uncertainty is bad enough even if there's no certainty for a bad hypothesis being true) _AND_ (ii) the ability to focus on an issue without thinking about possible sympathies for, or allegiances to, particular companies.
But again, there's a few vocal apologists and they are all quite weak. None of them has stood up to say that what Google does to those headers isn't infringing. So in a way they all agree with me :-)
Concerning LKMs, while one might try to come up with other derivative work theories, the use of copyrighted, GPL'd headers would of course be the best chance to prevail in court. All you would have to do then is request, in discovery, production of the source code of a proprietary LKM (in the US that's child's play, and even in Europe you could get to that point if you do it right). Then you prove that GPL'd material was part of the source code that was compiled, and you've won. Any other theories are far harder to prove, if they can work at all.