The problem, for me, is that it's something so huge that's only used as a cheap plot device - and not only is it never actually shown, but it's not even given any proper reason, it doesn't reflect any real underlying issues, it's just smoke and mirrors. If there is no real reason for people to trust vampires, if it's just a glamour, then just break that glamour and the problem is solved. If the only reason humanity is against the Slayers is because they're acting like a bunch of terrorists, then just stop acting like a bunch of terrorists and the problem is solved. There are some very relevant issues being tackled in Season 8, but this entire storyline - so far - is just obscuring and distracting from it.