I always thought that for me the unassuming, friendly looking guy next door is certainly scarier as a monster than the monsterish looking predator, because he can lure people in, it's easier.
Making scary movies and creating tension is very technical and it require a lot of coverage. It requires the stretching of time.
The process of finding an actor is always difficult and there's always so many variables that come into play. Also, actors sometimes carry baggage, fans associate actors with certain parts.
Making a movie is about following characters and embarking on an adventure with them, seeing their reactions, and seeing what they do, having empathy for those characters, feeling for those characters, embarking on this adventure.
