Kreia had proof that people could survive without the Force. The Exile isn't a force user. I also don't believe her ideal of destroying the Force is synonymous with her methods. The Dark Side of the Force corrupted her from her ideals because that's what the dark side does. That's kind of the tragic irony of her character. She could never really escape the force. She could identify the problem, but unlike the Exile, she was incapable of enacting the solution upon herself. It's a cool story.