Considering pretty much everyone was asking the same thing about last year's Stranger Things house (you know a house is bad when the first "scare" is a character arriving on scene and joining a group, not even going after the guests.) , it's not exactly far-fetched to imagine they'd drop the ball with Hill House.
@Clive nails it pretty well that Hill House needs grand set pieces that Hollywood hasn't really done. Add in a lack of creativity and overreliance on black walls and box scares, and you've got a disappointing house for a great IP.