I had hoped that one day we would have a well-maintained open source implementation maintained by a consortium including Amazon, Microsoft, Samsung, and others. Doesn't seem likely anymore.
As long as customers are OK with ads, I agree there won't be massive pressure to develop alternatives. But if other factors were changed, the necessary level of "I hate ad platforms" pressure might be reduced. I can imagine a world with only 10% of people using the alternative platform, but still having it survive.
I think the larger problem with my vision is simply that its not in line with the visions of the various competitors I listed. Everyone believed they could create their own separate mobile fiefdom (Amazon's Android fork, Windows Phone, Tizen, etc).
I wonder how viable that is.
It is totally possible to reimplement play services, Amazon does it anyway.
You would need to duplicate gmail and youtube though.
And also kickstart an app store good enough so that all the apps 99% of the users are looking for are there.
Even for a company as big as Microsoft, this looks like a huge task.