I don't understand, how is this different from Google acquiring and then selling off Motorola Mobility?
Although I suspect that Google's directionless approach does not help.
To speculate a little more wildly it's possible Google's motive is also to push the current Android manufacturers to "up their game" in the same way Google Fiber may have been a subtle threat to internet service providers.
As you suggest, perhaps this iteration of hardware will be like Microsoft Surface. Well built, slightly more pricey hardware that set the bar for the industry..?