I seem to recall reading more than once that he was upset that "Archie Bunker's Place"/"All in the Family" never had a final episode. That's quite understandable. I rather feel cheated myself, although the episode where Mike & Gloria move to California to me is when the show ended, and that would have been a perfect place for the show to have ended.

After Mike and Gloria were divorced, I think she (Sally Struthers) had her own show about Gloria and little Joey.

It would have been nice if there was an episode that gave some kind of closure. The show surely deserved this.