Where's the funny?

Right now one of Buffalo's local stations is playing the series finale of Seinfeld, and I'm once again struck by the vast difference between the potential hilarity of the episode's concept and actual hilarity, or lack thereof, of the actual episode as filmed. There was, perhaps, legendary comedy gold to be mined from the legions of memorable characters from the show's years coming back to gain some bit of revenge for the various ways in which they were wronged. Too bad the producers failed to actually mine any of it. Weird.