Yes, the show's trademark innuendo and misunderstandings could be funny, but what makes the show inherently funny is that the situation driving this situational comedy was a landlord who was tolerant of homosexuals but not unmarried cohabitation. Was there really a point in American culture when this was plausible? See also 70's, Homosexual, Sitcom.
"It doesn't make a difference what temperature a room is, it's always room temperature." - Steven Wright