I think that stupid (or at least foolish) characters are pretty much a requirement for a horror movie. But the thing with horror is there are so many kinds. For some, just having lots of blood and gore is enough, for others they want to see a horrible looking ghost or monster, and for others (like myself) the unknown, or the thing hiding in the shadows is far more terrifying than anything a film producer could put on screen. Having said that the creatures with no faces in 'Sapphire and Steel' scared the life out of me as a kid (and as an adult too) !
The Very first Halloween Film was pretty good in terms of being scary. Unfortunately , it spawned sequels and copy cat franchises that were unscary and terrible .
Friday the 13th( The Saga of Jason Voorhees) begs the question of why teenagers keep returning to to Camp Crystal Lake.