I think a better question might be why does DRM make people go crazy? There's no fairness issue here--no one has a "right" to purchase electronic content. It's a free market transaction.

Paper books offer a set of services (you can read them, loan them, resell them) or put them on your bookshelf and look at the spines. You're either willing or not willing to pay for those services. There are a great number of things that I'd like to have but am unable or unwilling to pay for. :)

Electronic books offer a slightly different set of services (you can download them, store huge amounts of information in a small format, search them). You can't copy them or view them on a different device in some cases. Sometimes you can only view them for a limited amount of time. Buy them or don't buy them, it's your choice--but nobody's rights are being infringed if Amazon doesn't chose to include all the same rights or services that you get with a paper book. It's not like they're suddenly applying DRM to the paper books on your bookshelves....