I don't just write horror. I'm a fan of the genre, and I get this delightful chill down my spine when it's done right. However, horror films exist with a certain stigma about them. Along with science fiction, it gets many nods for technical achievement at the Oscars, but little respect when it comes to the big prize of Best Picture. That tends to be reserved for heavy, inspiring, social problem-solving films. The Exorcist is still the only real horror film ever nominated for best picture, though there's some debate about whether The Silence of the Lambs qualifies as horror or thriller (it's both, actually).
Genre bias aside - really, the Oscars nowadays exist only to give actors and directors a pay raise anyway - critics often dismiss horror films as mere popcorn flicks. This is unfair, but with so many horror films released of late, there's an increase in movies of poor quality.
Here are some of the biggest problems.
Too much torture porn
Torture porn is a subgenre of horror heavily reliant on gore to shock the audience. This is when you've got a deluge of violence and mutilation, which has it's value in horror but only if it advances the story (as every other element ought to). A film like Braindead does have use for excessive gore because it's used in a comedic fashion.
Not enough originality
I'm not talking about only the remakes here. A lot of times, I see a horror film that follows the same old formula: filling the first half with most of the big scares and addressing and resolving the crisis in the second half. That's fine. In fact, that's the plot structure horror films are expected to use. But I often see films that merely fit the mold without trying anything new with the material. It Follows was a nicely original film in that the entity pursuing the characters was one I'd never seen before, and Inner Demons was a great departure from other tales of demonic possession by having drug use be the girl's method of keeping the monster at bay.
Not enough evocative atmosphere
I think most people forget that monsters aren't enough, and they don't realize that until they're presented with a situation where they're overwhelmed by the visual of a creature. A lot of times, horror can be even more effective with proper lighting, shadow, and sound (or silence). Anyone questions that ought to take a look at the Eric Bana film Deliver Us From Evil, which is about a cop investigating a string of demonic possessions in New York City. It does have the monsters, but also makes great use of songs from The Doors, especially during a very atmospheric scene in which Bana pursues a possessed man through the basement of an apartment building and the demon keeps playing People Are Strange in his head.
Seeing only one side of the coin
John Carpenter said that horror goes back to tribesmen gathered around the campfire explaining to each other where evil came from. One explanation is that evil is beyond the fire, outside of the safety of the tribe. In the modern sense, this is the serial killer stalking the alleys, the zombies lumbering out of the woods, the vampire arriving from his castle. The other explanation is that evil is something found within everyone's heart. We have this protective boundary, but the monster is already inside that fence among us. This is the monster who beats his wife and kids, the monster who steals her grandmother's medication because she's a drug addict, the monster who says she loves her boyfriend but then constantly cheats and berates him. While we have plenty of external monsters in horror, the internal ones often get overlooked, and the cream of the crop in the genre are those films that feature both.