I've noticed that, especially since the start of Fugitives, buzz about the quality of Heroes on SideReel has been, well, rather extreme.
There are plenty of people supporting every side of the issue. Heroes was only good the first season. Heroes is only getting worse. Heroes is no worse than it ever was. Heroes is getting better. Heroes is still awesome, just misunderstood. Et cetera, et cetera, et cetera.
I, personally, am of the opinion that the show's quality DID take a dive in Season 2 and hasn't quite regained its standing, though it is on its way. As for the reasons for this, I believe there were several key factors:
1) Bryan Fuller went off to create his own show, Pushing Daisies, which really showcased his talents. The show was (sadly) cancelled, but (happily) that has freed up Fuller to return and help get Heroes running again.
2) New shows always experiment. Always. And sometimes things just don't work. But that doesn't mean the show is getting worse. For more about this factor, I suggest you read this Masi Oka interview if you have not already.
3) WRITERS' STRIKE. I'm not saying it was a bad thing - far from. But it greatly shortened the 07-08 season and caused a great many narrative points to be shifted around. Heroes was hit hard by this change, I think. An entire chapter was abandoned, and the aired storyline was cut short. Writing is hard enough with full time and resources.
Season 2 is at the center of a lot of discussions about the quality of Heroes. Mostly as an example of how much worse the show has gotten. I myself am guilty of using it as such. HOWEVER, I think there were many extenuating circumstances involved in that drop in quality. Heroes didn't lose its magic, didn't lose its interest. It got a little lost and a little crippled. But I very strongly believe there is hope for future improvement and strength.
From one fan to any other who will listen, I ask that you just hold in there and reserve judgment at least until the end of this season. There's so much more we've yet to see. Heroes is in a rough spot. It's sick, but it's not dead.
Help give it a chance to recover.