@ninryu
This is like saying we should eradicate bears because they eat humans. Vampires have a right to live like any other species, and them being the natural predators of humans doesn't make them inherently evil. That's not how it works.
Being active in wildlife management and preservation there are two things I need to correct. First the minor nitpick: Bears don't eat humans. In fact, predators usually don't eat other predators (there's a reason humans don't eat falcons, wolves, foxes, badgers, et cetera). That said, bears might still attack other predators (incl. people) in self-defence or to eliminate competition.
Second: if vampires first appeared in the 17th Century, they're a neozoon. And invasive species are absolutely subject to targeted containment and eradication in their new habitats (although success varies), because the needs of the many outweighs the needs of the few.
That said, acknowledging that vampires can be reasoned with, let's paint them in the light of a civilization: A thoroughly stratified society with expansionist tendencies which relies on the exploitation of an out-group to sustain themselves, aggressively pushing to absorb others into either becoming (second-class) citizens or part of the exploited majority.
Those vampires are imperialists. And your mileage on imperialism may vary, but historically, the only diplomacy it understood were rebellion, insurgency, and open warfare. I for one am not ashamed to not recognize other's right to tangibly threaten the life of mine and the people I care about.
@PineconeJuice
It's chapter 3, and we're already getting dry-form informational dumps of lore. I never understood that. Do we need it? Does it change anything right now? Can't we learn about those in some organic way?
I don't get it. Even disregarding that it's a max. 2½ pages, isn't a signature of the 4th highest grossing media franchise worldwide to start with minutes of a slowly scrolling wall of text to set the scene? Sometimes the fastest, most economical and best way is to simply tell the reader, especially in a medium as pressed for space as manga.
And this series absolutely has some strong flaws, but with Utao having distinctiveness of a background character, the dumb cliffhanger take back, and the overall setting requiring your disbelief launched into GEO, this seems like an odd priority.