You can (and some people do) say the same thing about a web search engine. It doesn't exist and has no purpose without other people's content. However, it is not the content that the search engine is serving, it is serving the ability to search that content, which is something completely different. That's what's meant by transformative, and there are many many things that could not exist if you could not take other people's ideas, transform them substantially, and release the results.
Copyright and fair use is a balancing act, and I agree with Judge Chin that the benefits to having all of the printed word fully searchable (someday, at least) is a middling loss for the content creators and a huge gain for the public.
To address your specific analogy: you aren't being deprived of being able to release your work, and they aren't releasing your work with ads inserted, so I don't think it really applies. Google Books doesn't have ads today, but I wouldn't have any problem with them on the search results page (just like I have no problem with (text) ads on web search results pages) since they are in fact providing content very distinct from your copyrighted work.
Copyright and fair use is a balancing act, and I agree with Judge Chin that the benefits to having all of the printed word fully searchable (someday, at least) is a middling loss for the content creators and a huge gain for the public.
To address your specific analogy: you aren't being deprived of being able to release your work, and they aren't releasing your work with ads inserted, so I don't think it really applies. Google Books doesn't have ads today, but I wouldn't have any problem with them on the search results page (just like I have no problem with (text) ads on web search results pages) since they are in fact providing content very distinct from your copyrighted work.