Only for old people (such as myself) who grew up reading books. If you're starting an ebook platform right now, then the segment of the market that you should care about capturing and locking in right now has been doing most of their reading on backlit computer screens for their entire lives.
And when those young folks get to be old folks what is their eyesight going to be? It isn't just because what you are used to, the e-ink and using light is easier on the eyes.
With a backlight screen you are staring into a light.
http://mayoclinic.com/health/eyestrain/DS01084
http://www.ergoindemand.com/Eyestrain-Solutions.htm
Note, there are few super glossy e-ink displays. Nor are most books printed on extra deluxe glossy paper.
Sure, you can read off of a screen. What are the long term effects though?