I agree. I'm not wild about the "open" model they adopt - the code is (generally) open but the project certainly isn't and they do seem to play around with it to suit their commercial needs.
But given that Amazon have gone and lifted the Android code base and reused it without any endorsement or sanction from Google and largely not to Google's benefit, Google deserve some kudos for continuing to outsource Android at all.
If you release a project as open source having someone come along, repurpose it and use it is what you are hoping for. The entire idea is for people to use that source code that is now public to build new projects. You don't open source a project for the recognition. Why should it have to be sanctioned by Google? Why should it be endorsed by Google?
I can go out and download FreeBSD, strip all of the FreeBSD marks, and brand it bertBSD and I can do whatever the hell I want with it (following the license it is under). I don't need endorsement nor sanction from the FreeBSD foundation!
Well, to be fair: there are lots of reasons for releasing and using free software. Google's (as opposed to Android's) interests aren't necessarily served by someone else rebranding it. And a project generally is hurt by a fork. Having Amazon's even more walled-off fork of Android exist does nothing to help users of smartphones.
But your broad point is exactly right: we're all better served by working together on software instead of racing for parochial advantage by building on top of it without contributing to the whole. Open Source has lots of big advantages, but to do it "right", there are costs to be borne as well. The Linux community has on the whole found a pretty good balance between these concerns. The Android community has had some pretty bad missteps.
But given that Amazon have gone and lifted the Android code base and reused it without any endorsement or sanction from Google and largely not to Google's benefit, Google deserve some kudos for continuing to outsource Android at all.