When you make a purchase for the Kindle, you're not buying a book, you're buying the right to view the content of the book in a limited context.
Actually, that's what you do when you purchase any copyrighted work. Copyright law prohibits you from doing a wide variety of things with some things you buy - copying and creating derivative works being the big ones.
Except a physical copy doesn't disappear when the person who owns the copyright decides the store you bought it from didn't sell it to you the right way.
Not quite, copyright law prohibits you from doing some things with the presentation of the information such as distributing copies and creating certain types of derivative works.
I am free to do virtually anything with the original including archive for all eternity, loan out relentlessly, sell, or chop into small sections and sell the sections.
I can even copy within certain contexts (archival copies of software, for example) and I can create certain types of derivative works (parodies and certain limited educational uses for instance).
You are allowed to watch it with your friends though, of course that might depend on the country you live in. In Germany you are even allowed to give copies to close friends and family members (but you are not allowed to break copy protection).
You have a point that you can provide a "public performance", but as I understand it (clearly IANAL) that is defined quite strictly and you may show friends and colleagues in a private setting at will.
They gave a very public example of the problems with locked/controlled content and how it tends to directly oppose the consumer.
When you make a purchase for the Kindle, you're not buying a book, you're buying the right to view the content of the book in a limited context.