It happens in every horror movie - why? SPOILERS

Someone in the "group" says "No, we can't call the police! We'll be blamed!!" When clearly they would not. To this films credit they called anyway.
AND
Why does one person always lose their mind?
The mind is an incredibly difficult thing to lose. It never plays well.
AND
Why does someone always lose their *beep* in some kind of ridiculous manner (Ray) and no one just punches them in the head the way they would in real life? Man that scene of obvious self destruction went on forever!!

Despite those annoyances I've seen worse in a 12 day shoot.