Because Google didn't make that argument, no matter how terribly M G Sielger may misinterpret it.
"They’re doing this by banding together to acquire Novell’s old patents (the “CPTN” group including Microsoft and Apple) and Nortel’s old patents (the “Rockstar” group including Microsoft and Apple), to make sure Google didn’t get them;"
That's what Google actually said. Google partly owning them in concert with Apple and Microsoft does nothing given that Apple and Microsoft are the primary antagonists of Android.