Why The O.C. Was Canceled After 4 Seasons
In the early 2000s, Josh Schwartz's "The O.C." was the OG guilty pleasure show. It was basically a soap but a heightened and well-written one, set in California's Newport Beach, where rich people were the average citizen.
The series aired on Fox for four seasons, starting in 2003. In 2007, after 92 episodes (including a fourth and final shortened season that consisted of 16 episodes instead of the regular 24-25), Fox cancelled the series due to a steady downward trend in ratings.
In addition, a key narrative change in Season 4 served as a harbinger for the show's eventual end.
Marissa's death sealed the fate of the series
Most fans were extremely disappointed and disheartened when Mischa Barton's Marissa Cooper was killed off at the end of the penultimate season, and claimed the show never could recover from such a loss. No doubt, the bread and butter of "The O.C." was truly the complicated and tumultuous relationships (romantic and otherwise) that kept its momentum going with some juicy melodrama. With Barton's dramatic and unexpected exit, something vital in "The O.C." was gone as well.
Although creator Josh Schwartz tried a few different things plot-wise to establish new storylines in the aftermath of Marissa's passing, most of those have failed miserably. Later, he admitted that writing off fan-favorite Marissa was a mistake he regrets to this day.