Um, Google has actually worked very hard to de-couple parts of Android into separate apps, so that those apps can update without a carrier-managed total OS upgrade.
This has arguably negative impacts on Android's utility as a non-Google OS, but there's no question that this strategy was to help push updates to users faster.
This has arguably negative impacts on Android's utility as a non-Google OS, but there's no question that this strategy was to help push updates to users faster.