Inferno, Ring 3: The Gluttonous - Poetic justice?

In ring three of Dante's Inferno, the gluttonous lie in the filthy ground, all covered in mud and the filthy rain that falls constantly over them. They lie there, basically like pigs, without seeing or even knowing about the people around them. I see that as poetic justice for two reasons: they lived their life eating, and maybe behaving like pigs, so now in hell, they literally have to live as pigs would do. The second reason why I believe there is poetic justice is their life was shallow, empty and selfish, everything was tied to their addiction. So now they are condemned to live (not only as pigs) without being noticed, and they are given no importance whatsoever.

What is a just punishment for a murder?

I think that prison for life would be a just consequence for a murder in first degree. If the murderer took a life away, he should now pay with his. But what would be the point of taking the murder's life away, when the consequence should be for him to realize the evil that he has done? So instead of taking his life away, put him in prison for life, where he can regret what he did.

Rewrite

A lifetime in jail is a just punishment, because if he took a life away, he should now pay with his.

Allegory definition

Allegory: A story, poem, or picture that can be interpreted to reveal a hidden meaning, typically a moral or political one.