Horror as a genre within the entire spectrum of entertainment is extremely ancient. Plays, books, now movies and video games.
It fascinates and/or frightens people because it lets us explore, for lack of better words, the darker side of everything. Horror explores an actually quite vast array of subjects, as I can tell from the movie industry’s sub genres of horror, and in particular, the concepts usually attributed to certain sub genres.
Ghost movies for example often deal with regret, tragedy, secrets, and they usually focus hard on ’‘the past’’ and what its wrought. This is a very strong human element.
It would take me a little too long to break everything up and offer my opinion of which genre does what, and I’d probbaly go into it too deep.
So as a whole it’s just fun for some people, whatever deep rooted reason might be at play. A good rush, some horror is also very artsy, it can cater to many things.
I like nasty zombies and killer dudes with masks, and for me personally, I sorta got this crush on the eighties, so I like watching the horror culture from back then.
To return to my point of exploration, well yes, a lot of horror can’t be taken that seriously and it’s often grossly missproportioned when relating it to the real things it explores, exploits or makes fun of, but this the ’‘safe’’ way that some mentioned of looking into the abyss, so to speak. I mean why do people watch action flicks? Nothing you see in those would ever happen, but we like to escape to a place where it just does for a while. I’m starting to forget my point though…lol.
I think the closest thing I can come to answer if I were to speak generally, is what @stump and @Fiddle_Playing_Creole_Bastard said. Good answers there. And @Simone_De_Beauvoir too. Nice and simple, like a good slash to the throat. :D