I'm a mythology buff, so I could probably rant for some time about how vampires and their mythological predecessors were highly sexualized at least as often as not. However, I will refrain, and simply state that vampires are usually portrayed as sexual beings in both modern and pre-modern mythologies. Even so, people feel that there is some change. They feel that there is something sacred about vampires that is no longer as it should be. In other words, they're nostalgic.
We all do it. It's like remembering a time "when men were men." It's a nice idea, but the world doesn't work that way. Things aren't perfect just because they existed a long time ago. Those men who were men had problems too. They got scared, they cried, they wrote poetry, they cheated, they stole, and they did all those other things that humans sometimes do. That's because they were human, just like people are now. They weren't magically better people just because they lived a long time ago. The world doesn't work that way.
So why do we think like we do? We think back to "simpler times" and we imagine an ideal world free of poverty, strife, and discrimination. It's a perfect world, and it never existed except in our minds. The problem is that we forget we made it up. More accurately, we forget all the little details we had to leave out, like poverty, strife, and discrimination, to make our memories so perfect. And that's a problem, because then we think we can just go back.
It's good to have an ideal in mind. We must always strive to create the perfect world, even though we'll never really get there, because that's the only way we'll get closer to that world. The problem is that sometimes we forget that the world was always flawed. When the ideal is an idea, it motives people to move forward. When the ideal is a white-washed memory, it motivates people to turn around and go backwards. Since that perfect world never really existed, backwards is hardly the way to go (excepting cases where the current situation is abnormally bad, obviously; the key point is that it's okay to go back if one doesn't plan to stop moving forwards afterward). A perfect example would be the Victorian period of English history. We remember the Victorians as pure and chaste, if admittedly somewhat repressed. It's a nice idea, a simpler time when men were honorable and women were pure. We forget things like the rampant poverty, the barbaric medical practices, and the syphilis. Those pure and chaste Victorians? Their number one killer was syphilis. So yeah. Probably not so pure. Going back to their practices might not be such a great idea.
I guess what I'm trying to say is that nostalgia plays tricks on us. It tells us that things used to be better, even though a good many things used to be much worse. So don't listen to nostalgia. Take a good, honest look at your memories, maybe look at a history book to see what else was going on at the time, and then decide what was good about the past and what should be left behind. And then instead of complaining about how things used to be, go out and make something better. Someone has to. That's the only way we move forward.