Is it unfair to criticize Susan Boyle?

I find some criticism here today on YA of Susan Boyle's mental condition. I find it deplorable, to criticize her when those critics have not walked in her shoes !! Stop and think about Judy Garland, and Marilyn Monroe, to name just two stars of yesteryear. They also could not handle the pressures of stardom, and ended up being drugged for most of their lives, and in the end, died untimely deaths, possibly because of their inability to handle stardom. Do you think it unfair of us today to criticize Susan Boyle ??? I do.