Don’t authors and publishers have the right to be paid for their work?

Yes, and disabled readers are perfectly willing to pay to download books from Amazon just like everyone else. However, it is discriminatory for authors and publishers to charge disabled consumers more for an e-book than they charge the rest of the general public. If a person without a disability can purchase an e-book for $10, it is unjust to suggest that a person who cannot read that book visually must pay $12 for exactly the same e-book. The e-book being downloaded by the person with a disability is no different from the e-book being downloaded by the print consumer; the only difference is the method by which the disabled person will read it. There is no additional cost to the author or publisher incurred by making the book available to the disabled reader, and therefore it is unjust for authors and publishers to demand that readers with disabilities pay more for books just because they are disabled.

The water company does not charge separate rates for the use of water depending on whether the consumer is drinking it or using it to wash dishes; it simply charges for the amount of water used. By the same token, an e-book is not inherently visual or aural, and to claim that reading it either visually or aurally should cost a different price is discriminatory.