Because I am the all-knowing television god. Actually not, since I don't watch TV and something has to be completely awesome for me to get into it. There are a lot of great shows out there, and great reasons to watch them with a critical eye. I've been wanting to do a post like this for a while. TV (and movies) are a great way to learn something to apply to your writing, be it plotting or character development or dialogue or how to believably portray a platypus-bear, quickly and efficiently. Because of the longer form (the seasons) the characters are able to grow so much more and that makes them dynamic, REAL people, instead of just archetypes. TV is better than movies, in this way. Why else should you be watching them? Because I like them, and I think your life is incomplete without them.
As a writer, I watch it for a) the dialogue, and b) Detective Carlton Lassiter. Lassiter is the most complex character on TV right now, and I think it's interesting he's in such a goofy show. He's the straight man. The law-above-everything-else man. At first glance, you think he's arrogant and wants to take all the credit for himself. But as the shows unfold, you realize he wants to solve the case, no matter what, even if that means teaming up with Shawn and Gus (which he is lathe to do), even if it means putting himself down. He builds these insane barriers around himself and then he gets over them to help other people. Shawn and Gus are funny, but this show rocks because of Lassie.
Dollhouse. A Joss Whedon creation of awesomesauce. Like Firefly, this show is full of all kinds of characters, plots, and an interesting setting and premise, and was unsurprisingly cancelled by Fox. The show follows Echo, a doll without a personality who is imprinted with different personalities to serve different needs, as she become self-aware. The show is slow for the first five episodes because you don't know enough of the big story, but stick with it because the payoff is so good! I'm currently watching the series for the second time, and it sucked me in right from the beginning. Every character, even the dolls, have their own motivations and quirks, and the show has hilarity (Topher!) and badassness (Boyd!) in spades. This show is also available to stream on Netflix.
What do all these shows have in common (or, the moral of this post)? Each show has characters with distinct personalities and motivations. A wide range of emotions (funny and sad each have their place!). Characters may act differently depending on who they are with. The characters serve as foils for each other and cover the gaps the others may leave. All in all, stories are important because of the characters who tell them. Why do you think history textbooks are so dry and boring? Because there is no emotional value in just stating what happened. People care about other people. Make your readers care about your characters, really CARE, and they will be with you to the end.