Oooh! Typically I won't post in here because I'm not an anime fan, but this topic is something I've discussed in college and has always intrigued me. No, I'm not talking about cannibalism.
I want to start by talking about one of the greatest prose authors of the 20th century, Vladimir Nabokov. He wrote a lot of very cryptic stuff and scholars still analyze his work even though he died 38 years ago. See, Nabokov was in the school of believing that literature and art were not necessarily didactic, or in other words, he didn't have to believe or share the same ideas/idealism as his characters. There isn't necessarily a part of him in his work, but rather he just created it because he could.
Nabokov wrote one of the most disturbing novels of that or pretty much any century: Lolita. Ever hear of the Japanese term Loli? That's a direct reference to this novel. In it, the story is told in first person by the character Humbert Humbert, who happens to be a pediphile. He prowls this 12 year old girl and eventually has his way with her. The process is all too stunning and at some points (upon reading it), you almost cringe when he gets caught doing it. There's the part of you who realizes he's a very disgusting person and he should get caught, but the other part where you remember every time you've ever been caught on a lie or for doing something stupid. Kinda like almost every scene in Meet the Parents.
Hawkward.
So, why am I writing about some book written in the 1950s when the discussion is anime? Because the essence of seeing the cannibals as the protagonists to this anime you're referring to is very Nabokovian. The writers wanted to mess with you. They wanted to put a spin on something you've never seen before. They wanted you to sympathize with some very disgusting individuals. Why? Because their art isn't didactic. It should be taken as just that: art.
