Richard, I understand where you are coming from but I always have difficulty accepting the “copying = theft” argument. If I copy your dollar bill then you still have your original bill to spend. Yes copying may disadvantage the author but it’s a different thing to theft.
My own use of Google books has been very much like a library. I used them to research the history of Flea Circuses so was mostly looking at historic books from between 1850 and 1970. So some of the later books would still be in copyright even if the author was deceased. I was mostly interested in a few paragraphs out of a much bigger book. Once I’d found a book of interest I then tracked down a copy. These were in libraries (some private which I paid to visit) or on the second hand market. In the public libraries I paid to photocopy one of two pages from a book. So I paid to access a real book but money never went to the authors.
However, I’d also never have heard about many of these books unless they were digitised.
For me the ideal scenario would have been to be able to pay the original author for their few paragraphs, in the same way I might buy a single track from a music album.