Given that APIs can't be copyrighted, why shouldn't they have that particular cake for free?
(Actually, the current court ruling is that APIs can be copyrighted, but re-implementing them is fair use. My personal IANAL opinion is that that won't stand - it will either turn into "APIs can't be copyrighted" or else into "APIs can be copyrighted, and the copyrights are not worthless - you can't copy it and have it be fair use". We shall see. Nevertheless, at the time Google copied the API, the assumption in the whole industry was that an API could not be copyrighted. Your statement that Google "wanting their cake for free" carries a tone of moral criticism that is unwarranted by the circumstances.)