Why is it so hard for people to belive in ghosts?

i mean its not like ghost hunters is runing the T.V show to sell hats and mgs the show A Haunting isnt runing for credit and popularity of Sci-FI, dont you think if it were fake it whould be out already? I dont mean to protest bu all this jaber about truth beetween nobelivers is so short of a road and turns into a belief of noexistance and rejection.