This started with an off-hand remark on Facebook about the how Showtime series Dexter seemed to have lost its moral center in the fifth season. It blossomed into a discussion, and is now getting the full essay treatment. Massive spoilers ahead.
Seasons 1 - 4
Dexter is about the quintessential antihero--a serial killer trying to make the world a better place. To make the titular character work as a protagonist, the series relies on a sort of twisted morality by which an evil person can do good. Dexter is broken, sure, but the justice system is also broken, and he can satisfy his bloodlust while cleaning up after other people's mistakes. Now it may seem odd to talk about a show like Dexter as having a moral center, but really that's what the show's been about since Day One. The first season, in it's entirety, is about Dexter trying to reconcile the fact that he is a serial killer with his obligation to be a contributing member of society. This conflict ultimately externalizes with Dexter being forced to choose between his biological brother (a serial killer) and his adoptive sister (a cop).
Throughout, Dexter is defined by the way he straddles this line between needing to be a killer and wanting to be a normal person. Starting with Season 2, we see him start to wobble on this line. Now he has to choose what kind of relationship he wants to be in: Lila is the evil, Rita is the good. In Season 3, it's about friendship: Miguel is the evil, his old friends are the good. In each instance, he flirts with the evil, things get out of hand, and Dexter has to destroy the monster he helped create. Now it's worth noting that starting with Season 2, the series is no longer tied to any of the literary canon that guided the first season. And at that same point, the series began to make Dexter less and less of an antihero and more and more of a sympathetic hero. On the one hand, we see get to see new outward variations on Dexter's internal conflict. On the other, we've lost part of what made him so interesting: Dexter always new that he wasn't redeemable. But as long as he held onto his code, he could stay safe.
The apple cart got royally upset in Season 4, the strongest in the series in my opinion. Dexter has someone to study: the Trinity Killer, who somehow manages to balance being a husband and father with being a serial killer. He is the epitome of everything Dexter aspires to be: rather than walk the line between good and evil, Trinity embraces both. Dexter thinks he can do this as well, but as the season progresses, Dexter's delicately balanced illusion slowly disintegrates. The more he studies Trinity, the more we sees that Trinity is barely hanging on. He isn't, in fact, a loving father and husband, and he is unable to control his psychotic urges. But Dexter doesn't want to see that; instead, he continues to make compromises. Ultimately, he throws out the code, allowing the evil in him to run rampant. He actively disrupts the police investigation into the Trinity murders in order to kill the man himself, and Rita's death is a direct consequence of that action.
So, to recap, the moral center of the show had been that Dexter couldn't help being a monster, but as long as he followed his own rules, he could be a member of polite society. When he ignored the code, he was punished. If he had killed Trinity immediately rather than trying to study and emulate him, Rita would not have died. If he had let the investigation proceed unhindered, Trinity would have been captured, and Rita would not have died. The show stayed true to the clear, if twisted, morality that governs its antihero. And Dexter is violently reminded that he will never be normal. And now he knows it, and now he's saddled with a family that he doesn't have time for, but he can't get rid of them because he has to keep up appearances. The end of Season 4 set us up to explore a very dark place.
And then in Season 5 the writers were like "fuck it".
Having now seen the entire fifth season, I can take some solace in knowing that Dexter ended up where he should have at the end of Season 4... more or less. But the moral tone shift (absent of consequence, no less) is astounding. Dexter kills a random dude in a bathroom and... well... nothing happens. It's totally forgotten about, except that the memory of his dead surrogate father gives him a big thumbs-up for showing some emotion. He throws out the code entirely, bringing in a protege, improvising kill rooms, leaving bodies around all willy-nilly. It would be one thing if we were following the fallout as he slowly reverted to the monster, but throughout the fifth season, Dexter becomes more and more of a sympathetic hero.
This is a problem. We can accept Dexter as a vigilante killer precisely because he's not a sympathetic hero! Rather, he's a force of nature, and we're lucky that he's on our side. But now, Dexter is just a guy, right? He's just trying to be a good dad, and stuff. But that means that when he kills, we can't root for him any longer. So the counterbalance that, the criminals Dexter is pursuing have committed acts of unspeakable horror.
So, this is the new moral center of the show: "Revenge is a-okay by us!" And it's not just the revenge killings. Dexter kills an ex-cop, a crime that will go unsolved because the guy was trying to turn in Dexter for committing murder--which is a totally justifiable thing for a normal person to do! Deb catches Dexter in the act of cleaning up after a kill, but she lets him go (without knowing who he is) because she knows that he was just killing for revenge after a particularly heinous crime. Familial problems? Those go away after a few episodes thanks to a super-nanny and grandparents. Dexter spends practically no time being a father, but he spends an awful lot of time being a B-movie action hero, killing haphazardly and for revenge. In fact, in the moment in the show that's supposed to demonstrate him being a good father to Aster, he does so by beating up her friend's step-father. Haphazardly. For revenge.
And, oh yeah, what about the Fuentes brothers? The season starts out with two Tony-Montana-caliber hoodlums, one of whom eventually gets killed. The other... is never mentioned again. He just evaporates.
I don't want to say that I didn't enjoy Season 5 at all, because I did. It's still a fairly smart show with compelling characters and a nice hook, but this season just wreaks of lazy writing. The moral center, whole character arcs, and an entire antagonist were lost in the shuffle while the creative team abandoned introspection for moxie. Considering the show's origins as a philosophical exploration of the nature and purpose of evil... I'm a little disappointed.