I think “scan” here was in the sense of “scan the ISBN to catalogue the book”, not scan the insides. Since many of these are old books, many of them will not be

I think “scan” here was in the sense of “scan the ISBN to catalogue the book”, not scan the insides. Since many of these are old books, many of them will not be perfect bindings. Scanning their contents therefore either requires opening the books and moving the pages (as Google Books did) or cutting the spine, which would be highly unhelpful since that would preclude any rebinding of the books into anything other than a perfect binding, reducing strength, repairability, and the ability to fold flat.