Kreia is just a tired old woman that is disillusioned by the Light and the Dark side of the force. She said in the end that the Force has a "will" and seems to apply that she herself no longer wants to be it's puppet. I think her disillusionment began before she was stripped of her power because she created Darth Nihilious who if left unchecked would "kill" the force. In fact creating Darth Nihillious maybe the cause of her downfall. Her attraction to the Exile is pretty obvious. A person completely surviving without the Force, completely free from it's will is something she always dreamed about but thought impossible. Maybe that's why she's so disappointed with you in the end, because fear drove the Exile to sever his link with the force and it was not a concious act.
