There's this thing. And it irritates me.
Say you love a show. Watch it week after week, season after season.
Then you notice, slowly, that it's getting worse and worse each season. They are making up random storylines to keep things interesting. Everyone has hooked up with everyone else so many times you can't keep anything straight. (I'm looking at you Grey's Anatomy.)
There are many shows that the general consensus was that they overstayed their welcome. HIMYM, Scrubs, and Supernatural are the ones that always come up whenever me and my friends talk about this. We always come to the agreement that shows need to learn to go out on top, rather than keep going for the money and then fizzle out once everyone gets bored. Yes, some shows are fortunate enough to last ten years and still be able to finish strong. Friends is an exception to the rule.
Then, I started thinking about Sherlock (the BBC one with Benedict Cumberbatch and Martin Freeman). That show has three seasons, but only 9 hour and a half long episodes. And that is so awesome to me. It makes every episode special. Some TV watching is a chore to me now. I watch Glee still, even though I roll my eyes at every episode because of this weird sense of needing to finish the series. Going back to Sherlock, they could also go for years and never run out of stories. If a show like Revenge operated like that, we would still be in storylines from the first season, and we wouldn't be so confused.
So, I guess my point is that TV shows need to distinguish between running because the show is still great or running because the money is still coming. Because that could make all the difference.