Eyestrain/reading experience is based on many variables, not just screen technology. The lighting conditions are a big factor, and eink and LCD tend to work best in the lighting the other technology is not so good at. Adjusting LCD brightness based on lighting conditions also helps mitigate eyestrain with LCD.
So I think typical usage conditions will have a big role in what a specific user prefers.
I guess the other thing is that 'overall reading experience' supercedes eyestrain (although obviously significant discomfort is a huge negative in overall reading experience). Many people here don't like the 'flashing' that occurs with turning pages on eink readers. It doesn't cause eyestrain but impacts overall reading experience.
Finally, to categorize those who prefer 'eink' as simply outliers, is not much different than claiming eink is outright superior. How much eyestrain are we talking about? Of course how much more eyestrain one tech causes than another will vary from person to person. At depending on how often they use the device, the difference in eyestrain may not ever be noticeable. User preference will then depend on other factors- (battery life, color, page refresh speed/flashing, etc.)
Personally, I think eink is here to stay, primarily because prices have finally come down. Whatever the benefits of eink, it would have never gone mainstream with devices remaining at 2008 price levels. I can't wait for the Kindle 4!
