Come to think of it, its actually a very smart move by Google to limit access to their voice controllable app on a competitor's device that uses voice control to function.
However if someone (read consumer) has invested in Amazon's echo device, guess who will be getting the shaft tho...
Yeah, but that's nothing new for consumers. Even though we're used to all this inter-connected access across multiple devices, this is all still relatively new and the winners and losers of the online content and appliance wars haven't fully emerged as of yet, though there are some clear leaders. In the meantime, we may see some inconveniences. I remember a few years ago thinking Apple was crazy for not supporting Flash on the iPhone. Pfft.