Maybe it's just my level of expectation about what a handheld electronic reader should do. Books, sure, but also web browsing and email and all the other things a general tablet can do. I look at reading a book as just another tablet app. Why have yet another device I have to lug around with me, just to read books?
See, and for me, the Kindle is a great alternative to lugging around at least two books, more if I’m traveling.
I still buy and read physical books, mostly at home now. But reading brings with it much different expectations than I have with tablet activities.
When I’m out and about during the day, I’ll bring my iPhone and paperwhite, but leave the iPad at home.