I'm also worried about their increasing move towards taking Android at least partially back proprietary. The original idea seemed to be an open-source platform, which is a nice way of spurring innovation. But they've slowly been replacing components with proprietary Google versions, which is making the core open-source OS less and less maintained. My guess is that the goal is to make it more like a Darwin/OSX situation, where the core OS is open source but lacks all the interface elements and is not really usable as-is by competitors. What would motivate that? One guess is that they're more worried nowadays about Kindle-type competitors than they used to be, devices that build on Android but hook into an alternative (non-Google) cloud ecosystem.
Some examples: Messenger seems to be in the process of being phased out in favor of Google Hangouts; Gallery and Photos duplicate functionality to such an extent that I suspect one of them will not last; even the main keyboard is no longer open source, as Google has more or less abandoned the default Android keyboard and is rolling all improvements into the default-on-Google-devices Google Keyboard app.
The OEMs and carriers delaying updates. By moving as much code as possible out of the core OS and into apps that they can update via the Play Store, they managed to make an end run around the OEMs/carriers. Notice how no one is really complaining about not having KitKat - the majority of the important updates are available on all Android 4.x devices, since they're in the Play Store.
There's enough open source OS left for a rag-tag bunch of bikers ( http://cyngn.com/ ) to create an entirely independent open source mobile OS out of it.
Some examples: Messenger seems to be in the process of being phased out in favor of Google Hangouts; Gallery and Photos duplicate functionality to such an extent that I suspect one of them will not last; even the main keyboard is no longer open source, as Google has more or less abandoned the default Android keyboard and is rolling all improvements into the default-on-Google-devices Google Keyboard app.