With its fourth season, "Heroes" saw its fortunes plummet almost immediately. Once one of the most-lauded genre entries on the schedule, especially during its first season, the series suffered from a lack of consistent direction. Every season has seen a drop in audience, and many would argue that every season has seen a similar drop in quality. And sure enough, this time, there wasn't enough hype, audience, or interest left for NBC to keep it on the schedule.
It's hard not to place the blame right at the top: Tim Kring. Instead of sticking to his creative guns, he caved towards the end of the first season and abandoned his plans to tell one complete story with every season arc. What followed was a constant attempt to recapture the glories of that original voyage of discovery.
Every season was launched with significant fanfare, as if the hype itself could convince the audience that the sins of the past had been avoided. The third season was rife with problems, not the least of which a failure to remain true to the established character and timeline continuities. The "Villains" arc constantly changed the rules to suit the needs of the plot, even when it didn't seem all that necessary, and character motivations were all over the map. The second arc, "Fugitives", never lived up to the promise of the premise.
The fourth season seemed like it was going to start off well, with the return of Bryan Fuller to the series and the "Redemption" arc. But both bits of news turned sour almost immediately. Fuller left without warning very early in the story-breaking process, which suggested that salvaging the faltering series was simply too big an undertaking for any mortal man.
On top of that, the first wave of press releases for the fourth season were altogether too on the nose. The writers and cast discussed how the characters were going to seek redemption in an active capacity. And many thought the idea of a metahuman carnival was a bit too contrived, even with Robert Knepper delivering a near-perfect performance as Samuel Sullivan.
To the writers' credit, they did try to make changes to the format of the series in response to the harsh criticisms. The number of plot threads in a given episode were reduced, and while the pace was requisitely slower, this allowed for more attention to detail. This structural change was in and of itself positive; however, success or failure was always going to come down to the strengths and weaknesses of the story arc.
Almost from the beginning, there were signs of trouble. Many of the characters openly discussed their intentions to seek redemption, which left many fans wondering where the skills of the writers had gone over the years. Characters don't talk about seeking redemption; they either earn it or not through actions and choices. Instead of organically taking the characters in directions that would accomplish redemption (or not), the writers chose to tell the audience that they should accept that the characters were going to redeem themselves. It just doesn't work that way!
The writers also seemed to fall victim to that decision made back at the end of the first season. Because Kring chose to keep the same set of characters in the forefront each and every season, the audience became bored, apathetic, and occasionally hostile towards the subplots featuring the too-familiar faces. Other characters were shunted off into ridiculous and continuity-altering subplots. Because of the structural changes to the series as a whole, some episodes were left with only one intriguing subplot, surrounded by much more of the same tired old characters and plot.
The carnival characters turned out to be the one saving grace of the season. Without the likes of Samuel, Lydia, or the questions posed by the existence of a hidden refuge for metahumans, the season would have fallen apart completely. This strength, however, was undermined when Samuel's goals went from deliciously grey to utterly evil about 2/3 of the way through the season. It was almost as if the writers had no idea what they had right in the palm of their hands.
But perhaps the biggest problem was the same one that had been plaguing "Heroes" since the first season: the inability to close the deal. Ever since the finale for the first season failed to deliver the Peter/Sylar smackdown that was all but promised from the very beginning, the writers have continued to bait the audience with big payoffs, only to deliver small-scale resolutions. Even as the season crawled towards its conclusion, the writers seemed to be pointing to something huge in the finale.
Instead, it seemed like the writers just couldn't think big. Samuel's control over the earth could have pointed to a much deadlier plot to announce the existence of metahumans and their desire for control over their own destiny. Instead, Samuel conceived the deadliest classical music concert in human history. Add the unfulfilled hints that Peter would take the reins of leading the metahumans that were dangled in front of the viewers, and it just fell short.
Some cited the unforeseen Haiti earthquake as a possible reason for the late switch. However, it doesn't take much consideration to notice that the writers were carefully cultivating Emma for her eventual role in Samuel's endgame from very early in the story. In other words, it wasn't a last-minute decision; it was something planned ahead of time. And frankly, that just makes it worse.
Personally, I knew the writing was on the wall when the producers issued a press release, many weeks before a key episode aired, announcing that a character played by an original cast member was going to die. This turned out to be Nathan, a character already technically dead. It was an obvious example of screaming for attention at the expense of one's credibility. (And the less said about Claire's much-promoted foray into homosexuality, the better.)
The third season of "Heroes" earned a Critical Myth rating of 6.8, which is just below the average. The fourth and final season earned a rating of 6.3, which is a significant drop. With such a massive drop in overall quality, it's not surprising that the series was canceled. Despite its strong and popular beginning, "Heroes" may go down in the genre history books as a series that never lived up to its own potential, thanks to producers and writers that never understood why.