Good question and I think it's one we're meant to contemplate...

It's not only that they were brainwashed, but that they have no concept of meaning in a life outside of the life that has been outlined for them, the life they have been brought up to accept, of doners and carers....

They have no parents, no family, no culture outside of how Hailsham has defined their lives... It is a matter of identity to them, to escape would be a rejection of 'the self' and would leave a huge void in what would give their lives meaning. This is something people find almost impossible to do.

Instead of escaping they try to find meaning in their lives in other ways, (Spoilers) Ruth talks about her origin, Tommy tries to find meaning and salvation in art and Kathy accepts and commits to her role as carer. This shows that they are desparate to have purpose to their lives and indicates that they are far from being able to deal with the phychological toll that an escape would take...

@Markoff said:

I still don't get, what stop them from running away and living under false identity? Or are we supposed to believe they are so efficiently brainwashed they never figure this out, even very few of them at least? What about commiting suicide at the worst case so they won't get your organs and wasted all those resources?

Also what happened to those few couples per year if they didn't get deferal?

Would be something like this be even possible, since sure some countries would take these refugees and I can't imagine there would be worldwide consensus on such program.

There's a lot about this story that doesn't make sense; you raise valid points. One point that particularly bugged me was the apology by Ruth at the beach and the suggestion that she had always wanted to make it right for Tommy and Kathy so 'here, take this information about a deferral'. She waits 10 years and is nearing 'completion' and only by chance meets Kathy but she had this all ready to go for the handover of vital life saving information? No, this is implausible.

I get that this story is a fairytale, a parable: at the same time even fantasies must have an internal logic and this story just floats in a void with no connection to a reality we might be familiar with. 'What is the point of this story' does NOT stand as a trigger for asking 'what is the point of life?' or indeed any other question.

The pacing of the movie is pedestrian. This common conceit seems to be some kind of substitute for profound. Just slow everything right down to a crawl. Mulligan, Rampling and Garfield all do well with this low key material, and some of the support actors do well also. As nice as Knightley is to look at, imo she can't act, and this is really on show given the presence of her co stars and the anodyne script. Points to the design crew. Sets and costumes are all done very well.