> The majority opinion did not answer whether APIs are copyrightable in the first place because it was unnecessary to settle the dispute.

They didn't answer it. They assumed it. They couldn't reach the fair uses analysis any other way. No copyright, no infringement, no need to assert affirmative defenses like fair use.

> In reviewing that [lower court] decision, we assume, for argument's sake, that the material was copyrightable.

> We shall assume, but purely for argument's sake, that the entire Sun Java API falls within the definition of that which can be copyrighted. We shall ask instead whether Google's use of part of that API was a "fair use."

You can call all dissents irrelevant if you like. But Thomas' dissent addressed the issue of the case, and arguably more directly than the majority's. The Federal Circuit decision on copyrightability, for which the Supreme Court denied cert, still stands. Its importance, not its rule, is called into question today.