Earlier quoted context omitted.
Are you saying code which calls library functions should not be copyrightable? The Baker opinion can of course be used as argument pro-Google. But it is also just an "opinion". Each case must be decided on its own. I believe there is a big difference between scale and structural complexity with the (inter-connected) Java API and some text-book examples of accounting layouts. At some point quantity becomes quality.
I believe he is saying, and I would tend to agree, that it does not matter if Google literally copy/pasted the Java header files or if they had merely copied the API (ie. the same structure, sequence and organization) in a different language; for example by creating a Go package having exactly the same package structure and providing the same functions as the Java standard library. In both cases, they would have "cop…
So that case was about illustrating and explaining a method of doing accounting. There was no textual matter copied.
In Oracle vs. Google I believe the source-code of the APIs was copied.
Even if one would consider a way to do accounting an "API" an explanation and illustration of an API is not the same as the "API".
Explaining or illustrating a "structure" is not the same as copying that structure. Note that copyright applies to actual "works of art", not to abstract "methods". An API (as referred to in this case) is not an explanation of a way of doing things but an actual constructed artifact, source-code.
Think about books. Their content is copyrighted. You can not copy their content. But nothing prevents you from explaining and "illustrating" the content of a book, as long as you don't copy significant portions of the structure and ordering of its verbatim words.