I don’t get how any could say it’s not a horror film, either, and the people who have said as much who I’ve asked directly to explain it to me have thus far not responded. I’ve seen at least one review (listed on Rotten Tomatoes) that refers to it as “a drama marketed as a horror film,” though. I think in at least some instances the person saying this is making their case based on the run time of the film devoted to direct representations of “horror” content. If the film is (x) minutes long, and (y) minutes of that running time are violent or have a monster in them (or however they define “horror” content), then it’s a horror movie. Less than (y) and it’s not.