I find almost the opposite to be true. "Reasonable" my ass. I read on my iPod all the time. Every now and then I pick up a Kindle to try, half my family members seem to have one...just can't see the worship of these devices. So much easier to adjust the light in one small device in my hand than to adjust the surroundings of whatever room I happen to be in to fit the needs of a Kindle.
I've always hated the problem of lumen levels for reading, and I started reading when I was 4. (started hiding a flashlight in bed soon after that) Backlit screens for an ereader are exactly what I'd been wanting all my life, without knowing it til this decade.
Like I said above, maybe people should learn about something (like lumens) instead of just reading the latest tripe on a Kindle.
You may be able to read on an iPod fine, but could you do so if reading for 3+ hours without incurring blurred vision, headaches, or any other symptom? Maybe so, but for the
vast majority of people the answer is
no. I've adjusted the brightness appropriately on my iPad and iPhone, and I still get headaches after just 15-20 minutes of reading with a reasonable sized font nonetheless.
I for one read my Kindle in very close to or complete darkness (I have a lamp on a small table by my bed, like millions of other Americans), and when I'm done reading I will simply turn the lamp off and lay the device down. I'm not really seeing the alleged 'hassle' here with having to adjust to using the Kindle in every environment. The Kindle is by
far a more prolific e-reader outdoors (bright or cloudy). Not to mention indoors with incandescent lighting (approx. 700 lumens) the Kindle preforms very well with no adjustments.
When it comes down to portability and usability in an everyday environment for reading, the Kindle wins here again. My Kindle weighs 241g, and an iPad weighs approximately 726g. That's nearly three times as heavy, and for reading while holding the device/book with one hand (most comfortable for me) 726g gets very troublesome staying upright unless you're holding it with a death grip. I use my Kindle for about 20 hours a week. I charge it once every 3-5 weeks. When I had my iPad, it was glued to the charger every night, and during the day when I was not using it.
Essentially, while an iPod/iPad/iPhone may more adequately fit your reading needs, a Kindle or similar e-ink reading device is more adequate for mankind as a whole. There are more people getting tangible books through libraries, bookstores, their own collections, etc. than there are downloading eBooks, and between a Kindle and a real book, the comfortability of viewing both surfaces is nearly indiscernible; therefore, the Kindle, or similar reading devices is more universal, affordable, and productive when it comes to eBooks.