I didn't mean to make that comparison, I guess. I specifically don't own a tablet because it doesn't offer any really appealing use cases to me. I can't speak for the market in general, the iPad is a big-selling device, but e-readers are quite popular too[1].
I guess I want to wind this up; I never intended to lay in to your criticism of the eInk screen, simply to offer that my experience of people's use cases differs to yours. It's kind of redundant right now anyway, the number of hoops you have to jump through to turn a nook touch into a general-purpose Android box means that it's still not a consideration for most users.
[1] a quick google for "more tablets than ereaders" yields the converse http://www.google.com/search?q=more+tablets+than+ereaders