I haven't seen The Descent, but I must say that I respect your opinion. I fucking hate Napoleon Dynamite. Part of the reason is that I believe movies often get over-hyped.
I actually saw someone give Little Miss Sunshine a bad review. Little Miss fucking Sunshine. They were apparently too "hyped" for the movie, and it let them down.
Perhaps this movie was over-hyped to you, and whilst watching it you saw it's flaws, rather than its successes? I personally believe some great movies need to be discovered for yourself. Perhaps this film is one of them?
Anyway, I am none too big on the horror genre. All they're good for is helping guys get chicks into bed. One day I want to see a movie about smart people being killed. Not just smart people, but relatable people. Call me a pussy, but I do not do weed. I cannot relate to people who do. I see a character doing weed in a horror film, I distance myself from them, and when they get hacked up, I don't feel a thing.
There are two ways to make people relatable. One is to create the illusion of a blank canvas, where the viewer writers their own story for the character, and can project themselves onto them. The other is to create a character so detailed, that you feel their life presence, and when they are killed, you kind of feel sorry for them.
Most horror films just have 2D characters go into basements and get slashed up. Oh, the terror.
Oh, and gore does not equate to horror, mmmkay, Eli Roth?