Most subpar anime don't stick around for very long, either being canceled due to a lack of demand or coming to their natural conclusion in a few episodes. However, despite their lack of success, a few of these terrible shows have been, for whatever reason, greenlit to receive a second season.
Vampire-filled romance stories saturate every fictional medium, and as evidenced by Vampire Knight, anime is not excluded from this trend. Released during the peak of the Twilight craze, Vampire Knight follows Yuki Cross as she navigates Cross Academy, a school split between two different student bodies: humans and vampires.
In terms of production value, the series doesn't suffer in any specific area; however, its helpless protagonist does a solid job of covering the slack and turning Vampire Knight into an overly predictable slog. Cross' repetitive damsel-in-distress characterization holds not only her, but the entire show back, and it likely played a role in the series falling out of favor after the release of its second season.