Horror vs Whorer

I finished reading Dan Well's John Cleaver series a little while ago. Around the same time I finished watching the fourth season DVDs of Dexter. One thing occurred to me. While I liked both of them, and while they dealt with very similar topics, there was one thing that I had to give Dan credit for.
He left the crap out of his books.
By crap I mean needless sex scenes, an excess of blood and gore, etc.... Basically the checklist that most horror movies seem to use now. Now, first off, let me say that while I personally don't believe in putting those things into media, I'm not coming at this from a moral high-ground or anything. Rather I'm taking a stab at it from a literary angle.
I don't particularly like to read or watch sex scenes, but I will allow them if they make sense. For example, there were a few scenes of such nature in the Troy series by David Gemmell. I loved the books, and when those scenes popped up, they helped advance the plot. They made sense. Which is after all what writing a story is all about.

The Dresden Files by Jim Butcher is another such example. The point I'm trying to get at is that while these books have sex and violence they make sure to make it part of the story.
Dexter on the other hand, includes scenes and while a few of them may affect the plot, many are just bizarrely out of place. It frustrates me because Dexter is a really well written show. But it takes me out of the story whenever they splash something like that across the screen by reminding me that this is just a show and they are looking for cheap tricks to boost their ratings. The show is good enough to stand on its own, and breaking the fourth wall just because you think that you need to dedicate x amount of minutes to scenes of that nature cheapens the work in my opinion.
What I'm getting at is my own pet peeve with most horror movies. It seems that regardless of the plot, they share something in common: they all have teens, who, for lack of common sense, would rather have sex than get on with the task of saving their own lives(which I admit is theoretically true, but not every time), and they contain a ridiculous amount of just plain gross violence, that isn't really scary so much as it will make you uncomfortable. Again, I feel that this is a cheap trick. Psycho is a great example of creating suspense with good writing, and look how long it's lasted. Just my opinion, but I doubt that in 30-40 years we'll hold My Bloody Texas Friday on Elm Street with Piranhas up in the same way. My prediction is that Psycho, however, will still be around.
Storytelling is about telling the best story you know how to. If you think that you need to add things in so that it will sell better, you're doing it wrong I think. If that's part of your story, and that's the way you want it, fine. By all means, put it in. But it should feel organic, not forced like you went through in round five of revisions and added them in.