This is extremely myopic. One of the great benefits of e-books is that books don’t have to go out-of-print and (potentially at least) become hard-to-find.
What is the message they’re sending to customers who would like to buy these books? If someone wants to give them money for these products instead of (or in addition to) the more recent books, that customer doesn’t care why they’ve been “retired”. They just hear, “No, we don’t want your money.” At best.