This is not a real substitutable space. Yes, we have other e-readers. No, there is a market dominant platform and that has consequences.
Because book IPR is bound in past practices and publishers as a closed shop, the motivations to fix this here, are mixed.
As readers/consumers I think we are ill-served by the outcome.
I suspect Authors, and authors agents would agree. its not equitable.
Not the least problem is that book IPR is very nationally focussed. Kindle is a trans-national concept. The segmented market is hugely frustrating.