It’s easy to see why “Hereditary” was chosen to play in the Midnight section of the Sundance Film Festival. It’s a freaky trance-out of a supernatural thriller, all about a family that’s being torn apart by ghosts, and it’s full of things that would look right at home in the megaplex horror-film-of-the-week. It has séances with mysterious moving objects. It has decapitated bodies and crawling ants. And it has visitations by figures from the afterlife, who stand stock still and nude and grinning in a way that’s more insidious than anything in the “Insidious” films.

My question is: Why isn’t “Hereditary” part of the Dramatic Competition at Sundance? It appears the programmers may have some of the same anti-genre prejudice that the Motion Picture Academy does. They may have looked at “Hereditary” and thought: Very well done — but in the end, it’s just a horror film.