It's just a theory I have. Shows like Spongebob, Simpsons, Regular Show, and some others seem like they can keep going on forever while shows like Young Justice, Avengers EMH, Legend of Korra, Green Lantern, and other seem like they were in constant danger of getting canceled (with most actually being cancelled), despite fan support being great for them.
My theory for why there's this difference is because of the differences in shows. You turn on the T.V. and watch any episode of Regular Show or Johnny Test, I'll be them just having another misadventure. You turn on the T.V. and watch any episode of Green Lantern or Young Justice, you might be lost or unsure of what's happening because things and events from previous episodes are affecting the events of that episode.
The difference between the shows is in one, anything can happen in any episode and it tends to be contained to just that episode, while in the other there is an ongoing story and unless you started with episode 1, you won't follow it quite as well.
So the theory is that shows with an overall story are more likely to be cancelled than shows without an overall story because the shows without an overall story don't need build-up. You can watch any episode and judge whether or not you like it because most of the episodes in the series will be about the same quality, as they'd all be self-contained stories that are good or bad based on that episode. The episodes of the shows with an overall story build on top of each other, one after the other, so not all the episodes are the same quality. Some exist just to move the story along or to reveal some new detail that was not before known, changing perceptions of past episodes and making you wonder how it will effect future episodes.
Now of course the quality of a show depends on the show itself, so you can't say shows with overall plot are better than shows without it or vice-versa. But looking at this from a network viewpoint, the opinions of the shows without overall story would tend to be pretty consistent. "Did they like the episode, yes/no?" "What do they think of the show overall, yes/no?". While the opinions of the shows with overall story would tend to fluctuate, given that not every episode is as important as the other.
So which show are the networks more likely to cancel: the show where the general opinion episode to episode is "Yes, I like it." or the show where the network is unsure how people feel about it because episode to episode opinions differ?
It's quantity of the quality vs. quality of the quantity.
Please comment to share your opinion about this theory.