Murder, She Wrote has been accused of being formulaic, sometimes in very funny ways, but that’s not really true unless you construe the formula so generally that a show with a genre must be formulaic. (On that subject, you might want to read Writing Formulas and Formulaic Writing and In-Genre Fiction is Dull Outside of It.)
What people are really referring to is that Murder, She Wrote generally used very clichéd characters. Writers, businessmen, police detectives, lawyers, real-estate agents—these were all variants on the standard cliché of them. Businessmen did business and they cared about numbers and money, especially if the numbers represented money. Real estate agents were always desperate to make sales, no matter what. TV actors were always full of themselves and demanding. (When I say “always” what I really mean is “almost always.) There was a reason for this, though.
Once you subtract out the commercials, an episode of Murder, She Wrote were approximately 45 minutes long (once you subtract the coming attractions, intro sequence, and closing credits). That’s not a long time to tell a complicated story, and if—as I’ve done recently writing episode reviews—you pay close attention to how many plot elements there are in a typical episode, you’ll discover that they’re actually quite densely packed. Once I started describing and analyzing all of the plot elements, it started taking me about a week to review one. This comes from the need to establish why Jessica is present, to give several people plausible motives, to do some basic investigation to uncover clues, and to throw in a red herring or two. Once you consider how much needs to be done, it becomes clear that there just wasn’t much time for characterization.
The characters in Murder, She Wrote were not, in the main, clichés because the writers had no creativity. I don’t want to oversell this; the writers were TV writers. They churned product out on a tight schedule and were not, for the most part, brilliant people. However, they did tend to flavor their characters in creative ways, if sparingly. What they were really doing was using clichéd characters in order to save time. We’ve all seen the characters they’re referring to a hundred times, generally more developed in those other places. Even if not more developed in those other places, a hundred variants on the same idea fleshes it out in our imagination. This is shorthand.
Had Murder, She Wrote used really original characters in each episode, the episodes would have had to be two hours long. That is, they would have been movies.
This shorthand is also part of what makes Murder, She Wrote a kind of comfort food. We’re familiar with all of these characters; we’ve spent a long time with them and now we’re seeing them again. Sometimes even played by the same actors we’re used to watching play them in the old days. This isn’t really a coincidence, it’s part of the show’s theme that old things are still good.