Abuse of power, as simple as that.
Law enforcement, prosecutors, courts, etc have NO authority to "ask" Amazon to provide the information. That is a fishing expedition, pure and simple. An arrogant abuse of power by those asking.
The court, however, can "order" Amazon to provide the information. Amazon can then choose whether to obey or provide a legal challenge to the order. That is how the system is supposed to work.
Keep this in mind the next time the subject of government back doors in to encryption & communication comes up. These same people who are fishing for evidence would have broad ability to go fishing in to anyone's lives without a legal warrant.
As for me....the simple solution. No Amazon Echo, Google Home, Smart TV or any other spying device within range of my network.