Obviously exploring the idea is more important to Ishiguro than the realism - he doesn't set his book in the future or bothers to explain where the technology for the cloning comes from, just goes with the assumption that it's there. But as for people accepting their fate... I imagine not all of them, but if they've been brought up that way, in isolation from normal society, well, I at least had no problems believing it.

They are, but that's kind of the point, that they maintain this naivety and innocence because of their upbringing, despite being very much not naive in other regards.

That's not so much foreshadowing as it is just not taking a totally linear approach to the storytelling. I don't know if that was really necessary, either, I know what you mean... I'm sure there's a good reason for it whenever he does it, though.

Fair enough. The difference between sci-fi and a book like this is that in sci-fi, the focus is much more on the issue itself, while here the issue is just a plot device to create the characters and the setting of Hailsham, and the moral questions about whether clones have souls and all that.