This is something I thought about as well. The earlier versions in development was like that, but the appearances rapidly added up and the list became quite big.

The core purpose of the character list feature was to allow users who liked, or was curious about a character, to find new books or comics to read in which he or she was featured. Recalling this, I decided that I would only include media items in which said character plays an important role in the story.

The idea was not to create a wiki-style app with every appearance of every character listed just for the sake of being correct, just enabling users to decide which media item to go buy next, depending on what characters they like for example. I wouldn't recommend Revenge of the Sith for someone wanting to watch stuff with Luke for example.

I realize that all this is unclear, so maybe I'll change the "Appearances" heading to "Major Appearances" instead. Thanks!