My read on the Rabbit books is that Rabbit is the beneficiary of monstrous privilege, Rabbit is aware that he's the beneficiary of monstrous privilege, Updike is aware that he is the beneficiary of monstrous privilege, and the book is an exploration of what it means to be so privileged that you can literally get away with murder. I think we read the Rabbit books for the same reason we read Crime and Punishment, that is to say. I think Raskolnikov and Rabbit are of a type, demonic figures who nonetheless possess a charm or something else unnameable that makes them compelling. I haven't finished the series, though.