Q: Why can't audiobooks be re-downloaded?

Why can't audiobooks be re-downloaded? I recently suffered a hard drive failure and could recover my purchased music from iTunes but not my audiobooks. You have records showing I have PAID for them, they were all purchased through iTunes, they are just audio files like my music, but I'm not allowed to redownload my audiobooks? This policy encourages piracy and discourages use of iTunes. Why should I (Or any consumer) continue to use a service that doesn't cover me when I can go to a 3rd party like audible.com and be secure in the knowledge that purchases are protected?