I wish people would stop calling these vampires, vampires. They glitter in the sun, don't have fangs, can't be killed unless torn apart and then burned, and pretty much abandons every single rule that makes a vampire what it is.
I suppose you could "try" to defend it by saying, "Oh but vampires aren't real and therefore they can be mutated to anything the author wants". Well, ok, but if you want to play like then can't you label everything a vampire? If I write a story about a magical unicorn with no horn, is it really a unicorn? Or just a magical horse? If I write a story about a caveman that is super duper hairy and call him a werewolf, is he a werewolf, or a caveman? Hell there's virtually no difference between a zombie and a vampire is you want to play stupid like that. Let's rename Dawn of the Dead, Dawn of the vampires. Sound like fun?
And at the end of the day, even if they WERE vampires, would that make it a horror movie? Let's face it, the entire story is a drama/tweenangsty/emo/romance. There's nothing horrific about it. It's a sad excuse for prepubescent erotic fanfic that some dumbshit writer was lucky enough to publish. If this is horror just because it has "vampires" in it, then so is Harry Potter for having witches, and Monsters Inc. for having monsters.