I think Kelly directed a lot of negative energy in the house. She constantly remarked that she wasn't there to deal with any of the housemates, only to work on her issues. Of course, Kelly's issues were all b/c someone did her wrong, Kelly never caused anything. However, she never really worked on her anger and constantly directed her rath on everyone else. I also think Kelly is the type of woman who doesn't believe in therapy. I think she looked upon the other women as being weak b/c they were in the house and wanted to work on their problems. When Kelly was pleasant I always felt it was phoney, you could tell Kelly's real nasty personality at times on the phone when she was "real".
I didn't see any progress with Kelly, I think they felt she's gone as far as she could go and graduated her.