(Considering that many people sit in front of a screen during their whole workday and read stuff I do not think that hardware was ever the problem. I do not know why people think they would be unable to read books on a LC Display when they have otherwise no problem staring at such screens for hours on end. It’s about image, availability and price, not technology.)
Second, you probably spend a lot more time reading on a screen than most people do. If your day job involves using a computer all day (which I'll hazard a guess to a reasonable probability of such, given that this is hacker news) then you'll already have internalized and accepted the tradeoffs of doing a lot of reading on an LCD. But to someone who uses a computer say 1/10th or 1/100th as much as you do they have yet to come to that bridge, and when they do they have a choice as to the technologies they use for screen reading, the slight benefits of e-ink may be enough for them, even if it isn't for you.
There are a lot of computer users in the world who have yet to read, say, 1 thousand words of paragraph after paragraph of text in a single sitting on a device. To them the differences between reading text on physical paper, e-ink, or an LCD may be much more significant than for those of us who already spend our days staring at monitors and feel comfortable doing so.
But I would argue that more and more people are. And more and more might just be enough. A big minority in any richer country might just do the job.
I’m not sure whether LCDs will be inside the devices which finally bring digital books to the masses but I do think it’s a distinct possibility. I do think they are good enough.