I'm not particularly a fan of Susan, and as a singer, she has her limitations, but she clearly has a talent and a lovely tone to her voice that a lot of people love and connect with.
She also has some problems, but she had them before she became famous. Adjusting to fame is never easy, but I actually think the people around her have done a fantastic job at protecting her from the pressures and kind of schedule most newly fanmous singers are expected to carry out.
She has made a lot of money, enough to keep her financially secure. She doesn't seem to have extravagant needs, but she still needs to pay the rent and now she gets to do what she loves.
I don't care much for Cowell, but in Susan's case, it's really her manager who needs to take responsibility for managing her schedule to make sure that she doesn't take on anything that's beyond her, while allowing her to do what she loves. I think they do underplay some of her mental health problems, but that's probably because she has nothing to gain from having the tabloids gossiping about her.
It's almost as if some people want her to have a serious break-down, just so they can rub their hands together and prove their point that Simon is evil and it's all exploitation etc. I do believe a lot of the artists are exploited, but Susan appears to be one of the best protected artists in music, never mind the world of Simon Cowell.