It's just impractical to avoid all used books! Not only is it expensive to only buy new books, but they're meant to last indefinitely... which means passing them down, selling them to buy new-old books, lending them to friends. While I can understand why your husband might be a little icked out by doctor's office books, holding a grudge against all used books is unreasonable, in my opinion. ;-)
Never borrowed books from the doctor myself, but I would say about 99% of all of our books are pre-read.