Some large percentage of physical books really aren't a precious commodity. They may be precious to you as an individual but chances are no-one else is going to be that bothered. For example, a second hand book wholesaler I just found with a quick google will sell you pallets of books for 25c/book which would only go down as your purchase size went up. If they don't sell then it seems pretty likely those books are going to get pulped anyway.
If they were buying the books new and then essentially pulping them after scanning that does feel wasteful, but if they were buying in bulk from a second hand wholesaler then Im kinda glad the content of those books is going into something useful before they get pulped.