An API design is plenty creative. The bar for what is creative enough to get copyright protection is extremely low, basically zero. An alphabetized phone book is literally the example people have to use for something that isn't.
There's a reason the Supreme Court didn't adopt the argument you are pushing and instead ruled on fair use grounds: It's a bad argument because a large API is clearly a creative work.
A table of baseball batting averages or telephone numbers is not copyrightable, no matter how good or bad it is organized.