When it comes to obsessively policing the "correctness" of works within their chosen genre, nobody beats horror fans.
Sure, sci-fi readers may have us matched when it comes self-defensive knee-jerk reactions to what we perceive as anti-genre bias in the mainstream. But nobody can get as hot when proposing what should and should not be considered as a valid addition to our pet genre. You couldn't find a mystery fan who, even if their tastes ran towards the hardest of hardboiled crime fic, would not recognize the elegant classics of Elizabeth Daly, the juvenile Nancy Drew series, and the aw-shucks slapstick of Kinky Friedman as all belonging legitimately to the genre. Sci-fi guys regularly lay down definitions RE the scientific rigor of the romances they read, but they know it's bullshit: Not a one of them wouldn't count Philip K. Dick among their number and his works are about as scientifically rigorous as The Great Space Coaster. I can't imagine you hear many romance novel readers say, "I don't consider romances between nurses and doctors to be real romance. It's either lusty pirates with good hearts and the clever, but sheltered - don't forget sheltered, sheltered is the whole thing! - daughters of wealthy shipping magnates or nothing!"
But horror fandom, with rare exceptions, seems to exist in a constant state of self-induced appreciation pogromitude, a constant ferreting out of "not REAL horror," with bloggers, forums, and twitter feeds acting as a million little horror-centric HUACs. While few in the sci-fi ghetto would rail on about Artemis Fowl or The Hunger Game, the fact that tween girls enjoy the Twilight series is apparently a source of unending and obsessive focus for horror fans who, at their age, should really be minimally obsessed with monitoring and evaluating the behavoirs of tween girls. Seriously, boys and girls, it's a wee bit creepy.
The constant clash between horror's self-appointed purity police is lightly spoofed in the latest issue of Vertigo's Unwritten. (You can stop reading now Tucker, it's going to involve words and an inauspicious lack of female nudity; blame writer Mike Carey and artist Peter Gross.) The new ish features a cabal of horror writers who gather at the Villa Diodati, the Swiss timeshare at which Mary Shelly first conceived of Frankenstein and his monster, to discuss the importance of Frankenstein and argue about the genre. For fans, the clichéd creators and the works they describe are funny.
Here's the group giving introductions. Give it the ol' clickety click to embiggen.
Later, the Torture Porn guy and the Laurell K. Hamilton analog mix it up a bit. Again, the clicking's the trick.