because vampires are now depicted as sensitive, sweet and romantic eye candy basically... someone one day was like..."why is this so violent and horror like? this is a movie about a monster sucking the blood of people !! " and he spat in the face of Dracula and made his newest vampires pretty boys
Vampires are a simultanious manifestation of power (generally also they have wealth and good dress sense) and vulnerability (in an angsty way which appeals without being pathetic) in a tall dark and handsom package. Futher they generally use a mix of 'old world charm', long lingering looks and a touch of agnst to hook the lead female into a relationship. Then you have the usuall control and danger fantasies playing a role. It's pretty streight forward.