The Vampire Diaries often turned the villains into the heroes, and the heroes into the villains, and the eight seasons featured a ping-pong of characters being good, then going bad, and then back to good again.
The Vampire Diaries writers always blurred the lines of who were the heroes and who were the villains on the series.
More modern ideas of vampires have made them more sympathetic, even sparkly, creatures who have a blood addiction.
In early renditions of vampires, they were always the bad guys.