TV horror is having a moment. When American Horror Story: Coven, its third season, ended, it did so with 4.24m viewers. The Walking Dead's most recent season finale picked up a staggering 15.7m viewers. A&E’s Bates Motel, a prequel to the events of Psycho, has been renewed for a third season. Each of these series features big names, big shocks, and a complete disregard for our gag reflexes. However, despite our appetite for destruction (or at least to blood and gore), one gruesome addition to the TV horror canon is flailing.

NBC's Hannibal shouldn't be in trouble. It has a cast of TV and movie veterans (Mads Mikkelsen, Hugh Dancey, and Laurence Fishburne), it’s built on a bankable franchise, and features one of the most famous villains in cinematic history. It’s smart, it’s calculated, and it’s sleek. It carries the eeriness of The Silence of the Lambs, and the grossness of its sequels, and it’s been the subject of some censorship controversy – a fact that should draw audiences in, if only to see what all the fuss is about.

But audience numbers remain tepid. Since being moved to Friday nights, Hannibal’s ratings continue to battle, with its April 28 episode pulling in just 2.45m, compared to 3.35m for its season two opener (and 4.31m for its season one premiere).

Despite the varying successes of any and all Hannibal Lecter-related films, this character is untouchable in terms of instilling fear. He’s a cannibalistic psychopath – Hopkins’ depiction of the killer scared even co-star Jodie Foster right up until the last day of filming – and Mikkelsen does his terrifying chill justice. So while the nature of his relationship with Will may be the subject of playful “Fannibal” discussion on Tumblr, for casual viewers, Hannibal stands apart from its horror contemporaries. Without zombies and without witches, it is, perhaps, too real.

'Camp and ridiculous': Kathy Bates in American Horror Story: Coven. Photograph: FX Network/Everett/Rex Photograph: c.FXNetwork/Everett/REX

Hannibal is about the most depraved depths of human nature. Unlike the frequent camp and/or ridiculousness of American Horror Story and The Walking Dead, Hannibal focuses what makes us most uncomfortable (mental illness, for example), and Mikkelsen – true to character – never pauses to let audiences in. Hannibal as a series works like Hannibal’s mind: it is precise and fast. And to keep up, fans have to learn to think like he does, lest they get left back.

The series dares viewers to invest in the journey of a cold, unfeeling murderer. Whereas Bates Motel asks you to sympathize with Norman (a young man under the manipulation of his mother) and The Walking Dead uses zombies to justify its violence, Hannibal suggests you stick with a man whose MO is murder. Lecter is not a Dexter-style anti-hero, and unlike the criminals of Sons of Anarchy or Boardwalk Empire, he is not avenging those who have been killed or killing for business. He kills and then eats people because that’s what he is compelled to do.

I wonder if audiences are rejecting that darkness. While Hannibal has the top cast, the franchise, the legacy, and the artistic merit (this series is beautifully shot), it asks for a commitment and vulnerability that audiences may not be able to give – especially since Lecter is not going to reciprocate. It won’t offer campy closure in the spirit of American Horror Story, it won’t appeal to survivalists as The Walking Dead does, and it doesn’t offer a reprieve through dark humour like Bates Motel. Hannibal, unlike the others, simply dares you to enable pop culture’s most menacing villain, and then try not to side with him.