I think this reflects the changes in society between 1963
and 1971. Many "Beaver" fans feel that show ended at the
right time; JFK was assassinated two months after "Beaver"
left ABC, and during the next few years there would be more
assassinations, Vietnam (would Wally have dodged the draft?),
hippies (would Beaver sport long hair and smoke pot?), and,
increasingly, people looked at "Beaver" as reflective of a world
gone by, if it ever even existed (its real popularity came in the
'70s, when its fans, now adults and parents, looked back on it
and its era with nostalgia). By 1971 people were looking for sitcoms
with more connection to the real world, and "All In The Family" fit
the bill perfectly. Also remember that the fantasy sitcoms were
running out of gas by the early '70s; "I Dream Of Jeannie" ended in
1970; "Bewitched" in 1972 after three years of declining ratings (OK,
maybe Dick Sargent in place of Dick York had something to do with
it, too).