Most of the books I read are not fiction, so accessing endnotes is key. You can't do that easily on a Kindle, or any other reader. And when I'm sitting at home on the couch, reading, I prefer the bigger text of a book rather than the small text of a handheld device. I also like to have my hands busy holding the book, instead of fooling around with something else (spilling a drink, playing with the TV remote, forcing food in my mouth, etc.).