This episode from one of the better science fiction series illustrates one reason why science fiction and horror are two entirely separate genres, and when the twain meet, the result is often either disastrous, or laughable, or both.
Science fiction historically depicts humans, usually in some situation in the future and/or in another world not of Earth, triumphing over some abnormal threat. Humans may be depicted as good or evil or having some other human characteristics, but for the most part as rational human beings, whatever the motivations for their behavior.
Horror dramas are quite frequently populated by irrational idiots who ignore sane advice.
In "Whispers," two characters, at different times, wander into the woods at night despite admonitions to stay inside. Another character shouts crazily despite being told to be quiet. Some are rescued, others meet an unspeakable fate. These are what are known as stupid human tricks. Each time a character disappears into the dangerous night, one keeps expecting the background music to launch into "The Teddy Bear's Picnic."
In science fiction, one becomes part of an alternate world and gets blissfully lost in its mystery. In horror, the viewer's only purpose is to experience the fright of being scared, hopefully as close to death as possible without crossing over. This is why science fiction and fantasy make a much better pairing than science fiction and horror, and why suspense thrillers, well-executed, come off way better than bloody horror.