1. Form factor: They just prefer the feel and 'interface' of a paper book.
2. Lack of a compelling device (or perhaps lack of convergence): They don't own a reader (other than a PC or notebook) and can't take them with them.
3. Lack of content: Books they are interested in aren't available in electronic format
4. Distribution model: They don't like the DRM scheme their favorite publisher offers, or are otherwise unhappy with current offerings.
Maybe lively discussion from a prospective set of customers might spur the creator of the next generation of electronic book devices. Too bad the name 'iBook' is already taken."
What reason do you have for not taking up e-Books? Are they listed above or are there other reasons that you would like to add?