First of all, Kat has probably been teased endlessly for having a dad whose profession is "Ghost Shrink."
Dr. Harvey is only doing this job because of his selfish intentions.
Meanwhile, his poor daughter is getting harassed by the media all the time.
And he makes her move almost every week, limiting her chances of making any friends.
When they get to Whipstaff Manor and Kat claims to see a ghost, Dr. Harvey doesn't even believe her.
But when he sees Casper he's all surprised and screaming for his life.
He then locks his daughter in a closet with barely any air.
And despite being attacked by ghosts, he further endangers his daughter by staying at the house.
Kat gets asked out by a boy and just wants a nice dress for her Halloween party, but Harvey can't even give her $20.
And the day of her Halloween party, he goes to a karaoke bar instead of helping set up for her first big event.
He gets wasted and becomes completely incoherent.
He then breaks this glass for no reason.
And then he drunkenly stumbles outside and DIES.
Leaving his poor daughter temporarily parentless.
He doesn't even remember her, or their inside jokes.
Instead he makes a fart joke.