A requirement for a good survival horror game?
I think a good spot to start if you want an actual scary horror thing going on would be a taser strapped somewhere sensitive on the devs that goes off anytime a player hits something resembling a jump scare.
Will make for a strong encouragement to keep quality levels high in the game.
Please remember that jump scares are NOT scary, they are startling.
A sense of dread, helplessness and the unknown are key, but balanced with some manner of hope.