I feel the writers, namely Lindelof and Cuse, backed themselves into a time pressure corner and couldn't figure out how to clean it all up. So they fell back on "it's all about the characters" bit.
This is what bothers me. Lindelof is a terrible writer, pure and simple. He's responsible not only for the giant question mark that is LOST, but his stamp is also on "Cowboys and Aliens" and "Prometheus". I'm fearful because he's been given a writing credit on the new Star Trek movie.