The only possible way it can strike you as bogus is if you have never taken both of them outside and tried to read them. If the focus group was conducted in an office, then the results are basically meaningless.
I use my kindle on my boat. 99.9% of the time I'm sitting in the sun reading it. I can do that with a book, and I can do that with a kindle. The iPad or anyother backlit screen is just not an option. I can barely see my cell phone or camera screen on the water, but I read the kindle becuase it is a fundamentally different technology.
I got bad reflections on my iPad just sitting on my bed. It's like holding a mirror up in front of your face, and you have to adjust it to not catch distracting things.
This is bit of a deviation, but I am reminded of how my super Nintendo system has turned colors in part because of UV light.
I am curious if the kindle, in your use case, will- at the end of it's life- have distinct hand-prints where the original color is intact (if not physically smoother).
I use my kindle on my boat. 99.9% of the time I'm sitting in the sun reading it. I can do that with a book, and I can do that with a kindle. The iPad or anyother backlit screen is just not an option. I can barely see my cell phone or camera screen on the water, but I read the kindle becuase it is a fundamentally different technology.