Why in almost every story do people want to kill the vampire even if they havent drank anyone's blood or killed them? I just don't get it.

To prevent it from happening. I mean, if there was a blood thirsty, creature of the night, running about your town, I don't think you'd want it there too long either.

Many of these stories take place in the past. In the past, people weren't as tolerant of differences. They still aren't, some places.

personally, i blame it on the whole paranoia that runs through human nature. u know, "we fear what we don't understand" "we fear what we can't see" and shit like that? in those stories, we kill the vamps before they kill anyone becuz we're scared to death -no pun intended- of them. it's the paranoia that makes us kill them.