I got an Echo during beta, and there was no API at all. Later, they opened up the API. They've had enough time to make it useful by now (like, answering more than one question in turn!) but it's still not 100%.
Meanwhile, Google Home shipped last month. Building a developer community with necessary support and safeguards takes time. Doubly so if it's a win-or-lose battle for corporate dominance -- they can't just experiment willy-nilly with this, because one mis-step, and people won't trust Google in their homes anymore.
That being said, Amazon seems to have lost it with Echo -- it was the greatest radio for me for a long time, but since a couple of months ago, everytime I ask it to "shuffle my music," it plays approximately the same 20 songs out of my library of >5,000. Not useful; no response; no fix.
So, now there's a Google Home on my bedside table. So far, so good.
