Forcing equivalencies really doesn’t work. Tradpub isn’t the equivalent of selfpub and virtual books aren’t the equivalent of real. And then it gets worse: digital books aren’t the equivalent of digital music or digital video, nor especially are self-pubbed books to be lumped with Hollywood productions or studio music. In short, the reader of self-pubbed books could need a few more protections from carp material than the theater-goer.
This is also ignoring the issues that returning Kindle books for whatever is legit according to the purveyor, and the issue that said purveyor would undoubtedly rather sell a lot of books with the random return than sell a limited number of safe bets.