I agree with you, I made the switch myself. My point is that rather than enhancing the Android core, many of these closed APIs seem locked down soley to give Google more data, ie when that key API has the potential to be a data broker.
But since it's their internal infrastructure they can't not lock it down. Anything that is cloud-based has to be locked down. If at all possible, APIs for interacting with cloud-based services should be put into AOSP.