Current copyrighted novels by established authors do not have close substitutes. But there are other portions of the market:
Public domain novels (like most the classics we read in school) do have substitutes. Text-to-speech could make the difference in this portion of the market.
New authors who are just breaking into the market are not necessarily targeted reads. When looking for something new to read and the choice comes down between unknowns, text-to-speech could easily be a tipping factor.
As to your textbook case: Professor's think about supplemental stuff when making textbook choice. (I know, because I've done it.) If there are two introductory texts that would be fine alternatives, choosing one with more features just makes sense.
I agree the show isn't propaganda. They ran a news piece on the Fox News at 10 immediately following the premier saying that the approach probably doesn't work. I just took it as an attempt to get another police procedural on Fox with a unique twist, like Bones.
Trap full -- please empty.