I like the outcome from a public policy perspective. The policy the court has imposed is good for the industry. But let's make no mistake -- this is legislating from the bench.
The wholesale expropriation of an API is not the same thing as taking a small snippet of a copyrighted work for analysis, commentary, criticism, or scholarship. It is core the value of the work.
Indeed, it's the most important part, because it defines the functionality of the product. It is what the customer sees and interacts with. It is the means by which the customer gets value. You can completely swap out the backend behind the API and the customer will still get value. Change the API and the value goes away.
From a legal perspective, this decision is 100% wrong. The plain language of the law makes that clear.
What should have happened here is that Congress should have passed an amendment to copyright law allowing for fair use of an API. They should have done so after a free and full debate, with due consideration to all economic consequences.
It is not for our black-robed, un-elected overlords to make this decision.