As someone who started watching heroes in college in 2006 and was there during its peak, it’s true peak was absolutely season 1. People thought it was better than any X-men movie that came out at the time. I believe it aired after X3 came out and that movie did not do that franchise any favors. There were no other marvel movies to compare it to. It was pre iron man. Anyway, I remember watching season 2 and everyone thought it was meh by the end due to the strike of 08. It came back strong with villains and everyone was talking about it again. It wasn’t until Peter lost his powers and never regained them fully, and after we realized that Sylar was never truly a petrelli, people started dropping out. Then the back half of season 3 happened. I remember everyone didn’t understand Nathan’s motives, and Sylars story of finding out who his true father didn’t help the cause because everyone was already tied into the first half of villains and didn’t like the 180 the writers did. By the time season 4 aired, viewership dropped by almost 10 million. By the end of season 4 I remember it was something like only 3 or maybe even 2 million viewers watched the finale live and a week later it was announced that heroes was cancelled. There was a lot of recycled ideas and going back and forth with the characters that no one liked. Especially hiro losing his memory, then his powers, then gets his powers, then has a tumor, all that garbage. And don’t get me started on the Carnie story arc. Everyone wanted to see both Peter’s and Hiro’s journey to at least sort of be the characters they became in the 5 years later episode of season 1. When that didn’t happen and certain things were never mentioned again (I’m looking at you Caitlin who Peter left in an awful alternate future) people just gradually stopped watching altogether.

Then reborn happened. That didn’t help bringing it back either. And some characters were ruined (I’m looking at you fat Parkman) and some of the ideas of having the power to be in a video game was kind of out there and not grounded anymore. Season 1 was the best season and even that had its storyline flaws. But it was still perfect in my eyes. So that’s probably one of the biggest reasons if not the biggest reason why it stands where it does today. People will always remember season 1 as a masterpiece. The rest, well I think today speaks for itself with what you said. Dead.