" As a teacher, why would I go through all this trouble just to create a book than can only be properly viewed on Apple devices? I'm not requiring my students to by Apple products."
You might create a book if you worked for a school district that as policy provides iPads to the students. That's the value proposition Apple is offering: schools spend a ton of money on buying textbooks and buying new editions every so often. If Apple can make it cheaper to use iPads, then the school benefits by switching to iPads.
That's a fair point. I'm in higher education and our school doesn't buy books. I've created video lectures using Camtasia using a Wacom tablet and pen. The notes are in PDF format and I've created my own exercises. Students for one of my classes don't need to buy a book because I've got everything done for that course.
I'd like to use something like iBook Author but only if I can export it in a device independent way.
You might create a book if you worked for a school district that as policy provides iPads to the students. That's the value proposition Apple is offering: schools spend a ton of money on buying textbooks and buying new editions every so often. If Apple can make it cheaper to use iPads, then the school benefits by switching to iPads.