Joffrey is a little douchecanoe, but his death doesn’t bring Ned or Cat or Robb back. His death puts Sansa in the hands of a sexual predator. His death puts Tyrion in jail for a crime he did not commit. His death emotionally traumatizes Cersei.
“He has Jaime’s eyes. Only he had never seen Jaime look so scared. The boy’s only thirteen.”
Vengeance isn’t the point of ASOIAF.