There is merit to the questioning. I think the fact that Walking Dead seems to be also a finite story where characters don't exist in a vacum and every arc you see growth in the characters's life helps. I'm starting to wonder if the super-heroes shouldn't be more treated this way, as continuing growing saga. But it's hard to maintain the legimacy of the character(s) because there is so often a change of the guard as far as creators, editors, owners. American super-hero comics could use the European model of the same creators on a book for decades, that way it helps to keep with connection with readership, maintain fidelity.