I don't see the appeal of comics (but then I never grew up with them like other kids did, or do) but I love novels. I love books of all sizes (HC, TPB, MMPB) and I like the idea of carrying a library in my pocket so I can read to my heart's content without carrying around a dozen books.
Besides, as mentioned above, the eInk screen is more akin to an actual book than the backlit screens of computers, smart phones, and tablets, which makes it easier on the eyes.
Also, both the eBook readers and tablets are exactly like PADDs. If you think about the technology we have today and extrapolate out to the 24th century, we'll be well ahead of what Picard and his contemporaries have. It appeals to the ST fan in me.