Did you not see the preview for the next episode? No one is accepting Juliet into their society. Sawyer asked what the hell she was doing here and Sayid wants Juliet to reveal everything about the others or he's going to kill her. They are by no means happy that Juliet is here. Jack has built a bond with Juliet, probably because she reminds him of his ex wife. After Kate broke Jacks heart this is just another way for Jack to rub it in Kates face that he doesn't need her.