This would also seem to be problematic to reconcile with the ADA. This is definitely something that is a larger necessity for people with disabilities, and that the Author's Guild isn't seeing that shows how little they are used to considering this group, instead wanting to charge exorbitant rates for Brail copies of the book and thinking that addresses it. However this ignores the group of folks who have impaired motor control.
Try turning the page without using your hands and see how many books you'd want to be reading. Yes, there are various forms of voice command software, but all of it is still a bit buggy and not necessarily something you would want to use in all places. A couple examples of this would be a library, work place, or cafe' where you don't want to disturb others.