In most of the shows you listed, despite the popularity of the secondary characters, the main characters remained at the center of the show, the only one that didn't apply to was Jo Marie Payton, she was pushed to the peripheral of Family Matters.Its more like the Fonz, J.J., Flo, Urkel syndrome.... where a supporting character becomes more popular than the character the show is either named after or created for in the first place. In all those shows Happy Days, Good Times, Alice, Family Matters.... the main characters Richie Cunningham, Florida Evans, Alice, and Harriette Winslow were the reason for the shows.