I talk to y'all pretty often about the fact that horror can be very good for you. It gives you the catharsis of facing up to fears -- even if they're fanciful fears about vampires and zombies and monster clowns -- so you know you can face up to the real fears in your life. It gives you a safe and often fun way to confront terror.
But there are other ways horror can bring catharsis.
The revenge tale is certainly not unique to horror -- vengeance is a major motivation for characters in Westerns, comedies, and action movies. Characters on a quest for revenge appear in Hamlet, Game of Thrones, John Wick, Veronica Mars, Big Hero 6, Unforgiven, Death Wish, Django Unchained, Kill Bill, and plenty more. Where, after all, would Inigo Montoya be without his epic mission to gain revenge?