Once upon a time, vampires were seen as evil, yes handsome but really bad folks. Fred Saberhagen in his classic Dracula Tapes circa 1971 rewrote Stoker's novel to Dracula's POV showing Helsing was the bad guy and obssessive. A must read.
Then you had circa 1981 the Anne Rice Interview With The Vampire which changed everything. Yes vampires were killers but they had their own rich culture and could be also good and sympathitic people despite them being killers. Laurell K Hamilton dropped the killing part (except for the really bad vampires) but expanded on their culture.
Finally you had the birth of the paranormal romance with writers like Christine Feehan, Amanda Ashley would said "good vampires don't kill they are just bad boys looking for love". Ashley's books aren't bad, Feehan interesting but oh so wallowy in self pity. This peaked with Twilight. We also had the comic paranormal romance Lyndsay Sands' Argenou books were fantastic, Accident Vampire is my fav of hers. Then JR Ward Vampires are heroic good men looking for love. Now we have Fallen Angels "hey they aren't bad most are just bad boys looking for love".
Sometimes I wonder if King's Salem's Lot would be accepted today if he wrote it now not back in the 1970s, would he have had to have written in good vampires. Are we reaching or have reached a point where vampires are just bad killers is seen as wrong, vampirephobic (my word, I think) and good vampires must be included in novels? Whatcha thoughts?