This is a trend that continues to confound me. I guess an 80 dollar device can be viewed as disposable. But Amazon also does not have a policy for replacing Fire batteries, so I assume they are disposable too. Same for Sony readers and many tablets. It's not just an Amazon thing.
Sure, there will be better tech available when these devices die. But their primary purpose is to read books and tech improvements aren't really going to make a big difference in how that works.
The devices will only be "obsolete" in the fact that they will not function.
We are a crazy society that accepts disposable $200 electronics.
Well I'm off to drink some tap water I picked up at the store for a couple bucks (but it's in a nifty plastic bottle!)