No I don't think viewer's frustration with Kate is a result of Evangeline Lilly's acting. It is a reuslt of a problem most (even great) men writers have in developing women characters. The classic example is Hemingway. He had essentially two types of women in his writing - the "Good Girl" who was supportive, pliable and boring and the (now archetypal) Hemingway Bitch. Although a murderess!, Kate is essentially the Girl-Next-Door Good Girl. Every time they try to make her complicated, they instead make her, well, flaky and bitchy. The most obvious examples are the infamous Jealousy Scene and the gaping mouth attack on Jack before the Aljira flight. Take away those and I could make a pretty good argument for Kate's actions. If I could go back in time (ala Hugo to George Lucus) I wuld advise Carlton and Damon to have a women writer whom they trust to oversee the dialogue and actions of all the women characters (they all have Character Flaws). So cut Kate a little slack, she wasn't in the best of hands.