On Howard Stern's show this week, Jason Alexander gave us an answer to the long-standing Seinfeld question we didn't even realize we wanted answered: Why did the show kill off Susan? We just assumed that was Larry David's way of making a PSA about the dangers of expired envelopes, but according to Alexander, there were behind-the-scenes factors at play. Apparently, actress Heidi Swedberg was a wonderful person, but her comic stylings were so far away from the rest of the cast's that the regulars felt it was "impossible" to work with her. "I couldn't figure out how to play off her," Alexander explained. "Her instincts for doing a scene, where the comedy was, and mine were always misfiring. And she would do something, and I would go, 'Okay, I see what she’s going to do — I'm going to adjust to her.' And I'd adjust, and then it would change." It got so bad that Julia Louis-Dreyfus made a joke about killing Susan off, and Larry David promptly took her up on it. (Total Selina Meyer move.) Things worked out for Swedberg, though, as her character's death meant she had no involvement with that hugely disappointing finale.
Update: In a post on Twitlonger, Alexander apologizes to Swedberg for the way this story has blown up:
She is a kind, lovely person who undoubtedly worked really hard to create Susan and that character was clearly what Larry and Jerry wanted her to be for George. I just felt I was on uncertain ground in how to play off that character and I was always concerned that it wasn't working. And that's what I would voice concern about. But because the scenes were playing the way they were, the relationship with George and Susan sustained a whole season. People clearly liked the interplay even though I believed I was "off".