For the audience to care about a character, they need to feel what the character feels and vicariously experience the emotions they experience. The quickest way to get them to do this is to provide them with insight into the way the characters interact with their world, before they see them making important decisions.
Scary movies are hard to write. The Horror genre is sometimes looked down upon by audiences and screenwriters because of their low budgets, exploitative cheap thrills and over-use of blood & gore.
One of the main reasons that people watch films is to enjoy an emotional rollercoaster ride with no personal consequences. It’s a safe place to experience laughter, fear, sorrow, revulsion, delight… all in a fun emotional ride lasting roughly 100 minutes. If a screenplay is devoid of emotion, the film is seldom worth watching.
Screenwriters deal in emotion. To them it is a currency that must be exploited, and anyone that can contribute to this aspect of their craft is worth listening to. John Koenig is such a person.