Well I should clarify, since I was probably vague as hell about it (to avoid spoiler tagging), but since I'll have to-
What bothered my wife (and me to an extent) was that
It was just brutal to watch. The movie was not the greatest movie in the world by any means, but it had a certain momentum, and in my opinion, it was completely halted by that ending. I know that the perfect world ending doesn't often happen in reality, but I don't think any parent on Earth would ever want/agree to do what David Drayton did. I know I certainly wouldn't.