What follows is a detailed list of only five ways in which Heroes has failed its viewers. A full list would take too long and so this purely is the fist five that come to mind in no particular order.
Tracy Strauss
Ali Larter's contract with Heroes was a three season deal and therefore when they killed off Nikki/Jessica at the end of season two the writers had to figure out a way to bring her back. Enter Tracy, who apparently is some kind of manufactured triplet or clone, which the writers failed to fully explain presumably because they couldn't be arsed.
What the highly paid writing staff did do however was name Tracy's sisters. Of course there was Nikki, who we know, but the third sister was named Barbara. Hang on… wasn't Jessica Nikki's sister? The answer can be found here or if you want to do it the quick way I can simply confirm; yes she was.
Now there are two scenarios in which I can think that the highly paid writing staff made this error. One way is to presume that they knew exactly what they were doing and took care in inducing a character that totally contradicts another character's (played by the same actress) back story, all the while planning some elaborate end game as, say the writers of Lost, might do. Alternatively, and far more likely, the writers killed off a character two seasons into the actress who played said character's three year contract and had to think of a way to bring said actress back into the show. Being the highly paid professionals that they are they then half arsed some triplet/clone nonsense together and throw it on the screen giving absolutely no thought as to how this new character erases part of the old characters fully explored history.
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Sylar/Elle relationship
The first time Elle and Sylar encounter one another is in episode 2.11 - Powerless and here they give no indication of having ever met. The second time they are together is in episode 3.02 – The Butterfly Effect again they give no indication of having met before and it is also noteworthy that in this episode Sylar kills Elle's father and tries to kill her. Then comes episode 3.08 - Villains.
In this episode we learn that Elle went undercover and had a relationship with Sylar or, using his 'good guy' name Gabriel, pre the events of season one. After this they get all lovey-dovey in present time, in what I think of as a super powered version of this, and Sylar/Gabriel learns that he doesn't need to kill folks to get their powers after all. Sadly, three episodes later, he cuts her head off and sets her body on fire taking the old "treat'em mean" adage a tad too far.
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Sylar's Morality
In the shows first season Sylar is the ultimate boogieman loping off the tops of heads and removing parts of their brain with frightening efficiency giving the heroes a much needed and highly effective villain. By season two Sylar is relegated to a powerless border hopping bastard who cons a ride with nubile Maya and her red shirt brother. However, at the end of this season we given allusions to the return of the terrifying serial murderer we all knew and loved. Enter season three it's looking like he's back to him old self, attacking Claire at her home. But then he catches her.
At this point the highly paid writing staff take time to explain that Sylar does not eat the parts of the brain he removes (as was the popular assumption) and that, in fact, he does not apparently remove parts of the brain at all. Rather he just kind of looks and softly pokes at it until he sees how it works. Fair enough I suppose, except that season one clearly established that he did remove parts of the brain. And to this the fact that he replaces the top of Claire's head and lets her live and suddenly he's not as bad as you thought he was. Except you didn't think he was bad, this was a fact shown time and time again throughout season one as he butchered nearly everyone he came in contact with.
As volume three progresses Sylar is made out to be a guilt ridden vampire type akin to Angel until near the end of the chapter where he more or less says "sod that", cuts Elle's head off and kills a whole bunch of people without giving any indication that he gives a toss about any of it.
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Save the Cheerleader
- Hiro, sporting a sword, a ponytail and missing his accent delivers Peter the now infamous message.
Hiro comes from a future in which Claire is dead, a fact we now know is apparently impossible since Sylar told Clair that she could not die in episode 3.01. It's also worth pointing out that Hiro's message is completely pointless as it is not even Sylar who became said bomb (to be fair I believe this to be a deliberate red herring), and really even if he had been the bomb Claire's power would not stop him detonating, it would just heal him after it.
- Peter discovers that a virus will wipe out 93% of the worlds population.
Whilst there is nothing particularly wrong with Peter's visions/travels to the future this same chapter features premonitions on Noah Bennet's supposed death. One the one hand the highly paid writing staff tell us that the future is unavoidable and that Noah will die and there is nothing that can be done to stop it. Contradicting this is, of course the aversion of the nuclear detonation in season one and also that Matt, Nathan, Peter and Hiro manage to prevent the virus from being unleashed.
This chapter also features Caitlin, an Oirish girl that Peter falls in love with only to then loose her in the future and later, seemingly, forget all about her.
- Future Peter shoots Nathan to stop him exposing the truth about superpowers which then leads to a kind of power wholesale where everyone and his dog has a superpower.
It soon becomes apparent that Nathan's revelation exposing the Heroes has absolutely nothing to do with the mass production of superpowers. A cynic would say that Nathan's shooting was just a cheap ploy to make you tune in for the next season after the largely disappointing second instalment.
Further exploration into this timeline revels that Sylar has stopped slaughtering the innocent, donned a apron and has a son named after his partner (for all of two days), Noah. After presumable making some cookies for his would-be brother Peter, they are attacked by Claire and some generic bad guys causing Sylar to blow up in what must be the most pointless special effect ever. It takes all of seven episodes for the highly paid writing staff to destroy any possibility of this future.
While I'm on the subject of the future it seems pertinent to point out that with the death of Isaac Mendez in season one that the paintings of the future should have ended. Fair enough for Peter to have the ability but since then Hiro has also experienced it and it's now inexplicably part of Matt's power as well. One might think that the highly paid writing staff simply has no other idea of how to present a storyline, but of course, that would be ridiculous.
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Character Development
Based on various visions of the future their actions within the show both Peter and Hiro should be on their way to being more badass that Bad, Bad Leroy Brown, and he, if the song is to believed, was the baddest man in the whole damn town. Peter has shown hints of this by shooting his dad (even if Sylar caught the bullet the intention was there) and perhaps he may develop more in this direction as the show progresses (though clearly, I'll have to take your word for it). Hiro on the other hand is the same over excitable moron he's always been despite failing to save the waitress he fell in love with and burying a guy alive.
If I had lost a girlfriend to a brutal serial killer and then stabbed said serial killer at a later date as Hiro did you could pretty much bank of my enthusiasm about anything to wan quite a bit, especially if my particular enthusiasm was connected to how said girlfriend died. Most likely I'd take on board that that being a superhero may not be all fun and games as comic books (actually absolutely do not) make it out to be. If later on down the line another villain were to kill my dad then this would almost certainly put me in a generally grim disposition, and whilst I might deal with that person the same way; by 
burying him alive, this would almost certainly weigh heavily on my conscience. After all this I defiantly would not take my dead fathers warning about removing half of a formula from a safe (why didn't they just destroy it?) very lightly. If I did however unleash said formula, leading to countless deaths, then I think I defiantly would be a little hard on myself about it.
Not Hiro. He's forgotten all about poor long dead Charlie, didn't really give a toss about stabbing (and as far as he knew killing) Sylar, shrugged off his dad's death and the brutal punishment of his killer, and found it in his heart not to blame himself over the loss of the formula. Yata!
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Believe me when I say I could go on and on, but really I think I've spent enough off my time on this once promising and bitterly disappointing show.
