....Why are you putting words in my mouth lol? When did I say it's good story telling?
I know this, I'm speaking objectively about said tasteless pun. The point is, context is important:
There is a story being told about how Hiyori faced Orochi when he tried to burn her with him.
It then ends with her "literally" stating that coals are meant to burn as a pun. She is saying this to Orochi after he is set on fire. It sounds like it's being said in a flashback and everyone is repeating the line in the present.
Again, it's a poor joke, and for the 3rd time, I agree. But you are missing pictures and context. I guarantee you delivery of this line won't be so heavy handed to imply Wano wants to commit mass atrocities to a cursed family.
I also guarantee you mangaplus will probably just say "Coals are meant to burn" without context to the pun. Watch.