First, a disclaimer- this is not a Twilight review. Whether you love the books or hate them, you can already find a hundred online reviews that bear out your opinion. I would, however, like to talk about some cultural notions about vampires its criticism has brought up.
As you've probably guessed, the answer is complicated. The idea of the gentleman vampire has always been a strange one, but its roots go back far beyond Twilight. Let's take a look, shall we?
Picture a year without a summer, a young doctor cooped up with a bunch of temperamental poets and their female companions, all of them thinking up ghost stories to relieve their boredom. One of the female companions writes a story about a tragic monster, which she titles Frankenstein. The doctor looks across the room at Lord Byron, then writes a story about a Byronic monster, which he titles The Vampyre. It's not a very good story, and rumors will persist that he plagiarized it from Byron, but it becomes quite popular, and the image it presents of a handsome, seductive vampire will forever change how people think of the creature.
More vampire stories are written as the years go by. An Irishman writes a breathtakingly beautiful novella about a vampire named Carmilla and her romantic obsession with an innocent young girl. The amusingly titled Varney the Vampire: Or the Feast of Blood will also be published, showing a vampire who hates his condition and commits suicide by volcano. And then, the same year that a German doctor coins the term psychoanalysis, another Irishman writes Dracula and changes everything.
The title character is not a romantic, but he is a gentleman in the truest sense of the word- a man with wealth and a title. He enjoys beautiful women, but doesn't much care about their consent (his attack on Mina is written almost explicitly as a rape scene); he feeds on his peasants and their helpless children, literally sucking the lifeblood of the working class. He is everything evil and corrupt about the old world, and it takes enlightened science, American cowboys, and the "new woman" to destroy him.
When the movies came, Dracula came with them. When Max Shreck played him, he was a dried up corpse, his fingernails still growing, who spread plague and could barely pass for human. When Bela Lugosi played him, he was an off-putting but strangely fascinating foreigner whose eyes and voice hypnotized the unsuspecting. When Christopher Lee played him, it was the sixties, and Dracula was a suave British creature out to lower everyone's necklines and break up respectable relationships. When Gary Oldman played him, his relationship with Mina had gone from one of rapist and survivor to one of true love.
Somewhere along the line, the meaning of the word "gentleman" changed- it became something anyone could be, so long as they held the door for ladies and drank expensive wine. What once meant you trained as a soldier and were better than the lower classes now meant you were polite and good looking. Being pursued by a gentleman vampire didn't seem like such a bad thing after all.
Anne Rice popularized the conception of vampires as brooding and misunderstood, and while not every vampire author has followed suite, they have all had to respond to her. Buffy the Vampire Slayer had vampire love interests, but separated the times when they were romantic from the times when they were vampiric. Now we have Twilight, with a pro-abstinence gentleman vampire; many teenage girls swooned, and many nasty things were said on the internet about the intelligence of females.
With all that said and done, where does that leave us? Is the gentleman vampire the only way to go, and has the vampire in general been thoroughly domesticated?
Of course not. If you want bestial and ugly vampires, there are writers and directors who agree with you (Guillermo del Toro wrote a book with that in mind, and from what I hear it's quite good.) I don't think we should give up on the gentleman vampire, though; after all, the Victorians sanitizing stories about fairies hasn't stopped the Fair Folk from being used to chilling effect in modern fiction.
Maybe we need to go back to Dracula and Carmilla to understand it. Think of someone wealthier and more powerful than you, who still wants what little you have- your loved ones, your body, your blood. Think of a relic of the past that refuses to die, dragging bloody tradition into the civilized world. Think of something devouring you while dressed in fine clothes, all because they hunger and will never be sated- and as a lord or lady, they have every right to do so.
I don't know about you, but I think that sounds pretty damn scary.