Horror characters and/or plotting can sometimes be painfully dumb. Supernatural mostly avoids this but every once and awhile it crops up. Sam and Dean are freaken' idiots in this episode as is the family. Even the "ghost" behaves in a completely illogical manner. The episode is always a chore to sit through when I re-watch the series because of this quality.
Worse the final scene of Dean confessing his sadism is not needed. The prior episode ended with a similar confession that implied what this what spells out. Maybe if the Winchesters didn't lose their common sense here the final scene would play better. As it is it is insultingly convert subtext into text.