Just imagine if they had put the same effort into making a usable Android app, then the author wouldn't have bothered. In some sense it's negligence on Amazons part.
Years ago I dropped buying stuff on Amazon, because they can't match prices, shipping times and the site just invites scams, but I kept buying eBooks, because my old Kindle is sort of amazing. Then they started messing with the Kindle platform as well and now I just buy physical books from local retailers.
But I still think the better option is to never give any money to Amazon.