I direct you to ArvGuys answer to your comment, so I don't have to repeat everything. And Bram Stoker did get his inspiration from different mythologies. And as ArvGuy said, just because, there are some stories, that might take a funny turn, in the overwhelming majority of the stories, vampires are indeed fearsome and dangerous.
Finding inspiration is not the same as an ethnographer recording as much of the original folklore as possible. Fictional stories, whether teen romance or horror, are not a measure of popularity of those beliefs, but of the popularity of the story. Whichbis why I don't think that the Western literature is representative of the vampire mythos, especially since to my extend of knowledge most of the Slavic folklore never made it West.
As with any commercial products, the tropes that are portrayed in the media (including games) change based on what sells well at the given time. This is also why Astarion is popular, he reflects the current trend.
