Was TV always so dumb and predictable? I've been tuning in to some classic shows after visiting home for Christmas, and it's striking how even ordinary sit-coms from the good old days show craftsmanship in their writing. Nothing mind-blowing, but novel and unexpected enough to catch your attention, and with the narrative threads woven together naturally.
This prevents the tedium and predictability of more recent comedy shows and movies where one major thread is pursued. Two equally important plotlines allow the possibility of a problematic interaction which is later resolved. With one, the only thing that can get in the way of the plot advancing are separate little obstacles that are eventually surmounted. The weaker strength of these often contrived obstacles don't allow much tension to build up -- you sense that the main plotline is too dominant, and it'll just bulldoze clumsily over the mini-obstacles. If there is a second plotline at all, it unfolds entirely independently of the main plotline. Family Guy on TV and Superbad on film are two examples of this recent trend toward comic narrative monotony.
And the unpretentious nature of TV and film from back then steered clear of the opposite extreme, where two supposedly strong and independent threads are headed on a collision course that you can see coming from a mile away. That announces the writer's authorship too loudly. It also defuses the unpredictability that comes from an episode where the two threads have no obvious relationship to each other. In this latter case, you're wondering, if they interact at all, how and when it'll all come together. It keeps things exciting.
An example of the telegraphed-crash approach is the movie Rushmore, where early on two main characters first develop an unusual friendship (one teenaged, one middle-aged) and then fall for the same woman. It's obvious how it will roughly end, since the woman is an adult teacher at the school where the younger guy is a student, while the middle-aged guy is a wealthy industrialist. Clearly she'll choose the older over the younger of the two. Whatever other little surprises this may allow, it still gives the movie a fatalistic rather than spontaneous quality.
I can't think of sit-coms that go to this other extreme, perhaps because the narrative structure is more suited to feature-length comedy-drama movies. I mention it mainly to show that older comedy shows maintained an artful balancing act, not merely choosing one extreme over another.
To give one quick example, I just saw a 1978 episode of Three's Company which begins with two separate plotlines: 1) Jack sucks up to Janet in the hopes that she'll give him, rather than Chrissy, a pair of Frank Sinatra tickets so he can impress a girl with a classy date, and 2) Mr. Roper buys a parakeet as an anniversary gift for his wife, but gives it to Jack, Janet, and Chrissy to watch over it and keep it a secret before the day arrives. These threads have no obvious connection at all, and don't interact until near the end.
Jack has won the Frank Sinatra tickets and starts getting all swaggery as he calls up the girl to ask her out. In his excitement during the phone call, he plops down on the couch and squashes the box that the parakeet had been kept in. Mr. and Mrs. Roper show up so that he can present her with her gift, but with the bird dead, Jack quickly improvises and hands Mrs. Roper the concert tickets as the anniversary gift, with Mr. Roper playing along, his wife none the wiser, crisis averted.
In a final flourish, Chrissy reveals that she'd let the bird out of the box earlier, so that Jack has sacrificed his tickets -- and a good shot at scoring with a Swedish babe -- all for nothing. I think that was the gist anyway, as I got distracted at that point by the credits rolling in a pop-up box as the show was still going. Even re-runs these days are sliced up to fit in another 3 or 4 minutes of ads.
In any case, the interaction between the two plotlines was not foreseeable, and neither was the resolution. Instead of mindlessly marching forward, these ornamental twists and turns give the show a spontaneity and energy that's been lacking in more recent sit-coms. It's not the stuff of storytelling legend, but then it's only meant to be an enjoyable 30-minute romp, and surprises like that make it worth tuning in for. You don't really notice how boring the newer TV shows are until you watch something from a time of skilled narrative decoration.