Why the fuss? Amazon sold people a license to use the content in a limited set of ways, then withdrew that license. It's just like a rental car company ringing you to say the car you got isn't safe and sorry they don't have a replacement available. Kinda tough on you, but better than discovering exactly how unsafe it is. Getting whacked for a million bucks or so for each book (RIAA numbers) would hurt way more than losing access to a book.
I look at DRMed books as rentals. You don't own anything other than a restricted right to access the book in a narrowly restricted set of ways. Just like renting a video or anything else. Any time the seller likes they can yank the content. That's never been a secret, it's happened before and it will happen again. If you don't like it, don't rent books.