I'm not sure what the intention here is.

Number of seasons isn't always a good thing. Especially for a story driven show. Walking Dead's suffered in quality for a while, yeah? While, from what I've heard, Breaking Bad ended on a good note. GoT supposedly had as many seasons as it wanted, but the creators wanted to be done with it, and look how that turned out… Dunno much on Firefly. Did it leave a lot of unresolved story?

Of course, then there's the Simpsons, which has been a shambling corpse for years.

While each show is unique in how it goes forward, it usually does seem like the longer one goes on, the more of a chance it has to drop in quality. Guess it could also be up for debate if it's better to have a poor/bad ending or having none at all and at least have the creators quit while they're ahead. I know I've seen some people ignore later seasons of a show if it's bad and just accept that a decent ending will never happen.