Kelly is the worst mentor in X Factor history.
She chose Sophie over Amelia.
She destroys Janet through poor song choices, and generally failing to connect with her.
She has allowed Tulisa to control the narrative around Misha....which has killed most of her support
She couldn't bring Sophie out of herself.
She flees the UK on a phoney pretext...possibly as a stunt, at worst because of unprofessionalism.
Saying all that...I don't mind her. But she is a bad mentor.