Moreover, all userspace programs that use this information (by linking against glibc) would be considered derivative of the Linux kernel. All userspace programs that link against Windows' C/C++ runtime would be derivative works of the NT kernel. And so on.
Linus himself has asserted that the copying of such APIs is considered "normal use" and that such programs are not considered derivative works [2].
[1] http://www.fosspatents.com/2011/03/googles-android-faces-ser...
[2] http://www.groklaw.net/articlebasic.php?story=20110322014831...
Google's case is different: They have created a platform that uses APIs from a different vendor's plaform (Sun) and while Sun would have been perfectly happy to grant their own users permission to use the APIs, of course they have no interest in Google's customers being given that permission.
The whole basis of assuming that anyone can use an API that you write is that "anyone" is "all people who you have permission to use your software in the first place". Of course it limits adoption of your platform if you restrict who is allowed to use it, but so does charging money for it. Some people choose to charge money for their work, some people give it away.
Logically I can't see why an API should get copyright protections. By its definition it is a interface, and the moment you start allowing restrictions on implementing an interface your killing competition. It seems that in almost ever other field fair use has decided that whatever is required for compatibility is not copyrightable.
That said my beliefs and the law can at times be completely different things...
And your argument about Wintel machines is actually backwards. Because if APIs were copyrightable there would be MORE competition in that circumstance. Due to less standards.
I am actually in favour of having standards organisations take a greater role in pushing real standards rather than de-facto ones.