Lilah Morgan was the most adult (and not just in the sense of adult entertainment) person on the show. She knew the consequences of what she was doing and never complained about having to pay the price. And as just an additional justification, she had joined Wolfram & Hart to ensure her mother got the best old-age home money could buy. We see her as someone who has psychologically left home, established herself, made her own choices and not been the victim of some traumatized past that could excuse anything she did. As a villain, she was one of the best and her scenes with Wesley were scorching hot. We could have used more of her on the show.