I've misunderstood jahenders' post, who seems to misunderstood your post.
The problem with your idea is that in the 1960s the stations believed that the audience is stupid and cannot follow more than one plot and plots spanning episodes or is interested in the private lives of the characters. And remember that they were also not interested in broadcasting episodes chronologically. Much of the ideas needed for your idea were developed in the 1980s (see Hill Street Blues).
The problem with your idea is that in the 1960s the stations believed that the audience is stupid and cannot follow more than one plot and plots spanning episodes or is interested in the private lives of the characters. And remember that they were also not interested in broadcasting episodes chronologically. Much of the ideas needed for your idea were developed in the 1980s (see Hill Street Blues).