I don't rent many e-books from them since I have hundreds unread through purchasing and Kindle Unlimited. I mainly got them for Audiobooks. However, I have borrowed one or two and use my Kindle Fire for it. It does bum me that it does not work on e-ink, but that gives me another excuse to justify a Kindle Fire purchase -- this was before I got addicted to games on the tablet
As for the authors pushing for the change, not sure. I subscribed after all that. I don't mind some restrictions, honestly, due to the market. To me getting 2-4 audiobooks out of it for under 10 a month is an excellent deal. I don't listen to more than that regardless.