Well said! I think only someone who has read less than five books can entertain the idea that a plot line has to be unique (that, or someone who simply hasn't been paying attention. Good style and good characterization make stories live, the stories are the same, maybe because the human mind finds the questions these stories ask (who is this stranger? where is she going? what's wrong?) necessarily interesting. Asking that every story have a unique plot is like asking that every person have a unique skeleton: sure, there can be a bit of variation, but without the same basic design the thing won't work as it's supposed to.