With Supernatural closing its doors after fifteen seasons worth of plot lines, fans like to the show for the best moments it brought them. There are no short of quality arcs here, and there’s no doubt the replay value of the show will remain high even after its conclusion.
However, there are certain other plot angles that fans have come to hate, mainly because they ended up wasting time in seasons and at the expense of the likability of the characters. Still, it’s important to the bad times to appreciate the good ones.
The Entire Leviathan Arc
Making monsters the main villains was always going to be a risk. The Leviathans were shown to have an edge because of their intelligence, only to become the run-of-the-mill monster because of their weakness to Borax.
Due to their lack of threat, along with the fact that this storyline killed Bobby off for no reason, took the Impala away for most of the season, and the slow pace of the story overall, the Leviathan arc is ed as one of the biggest misfires on the show.
Human Castiel
Everyone likes Castiel to be the clueless angel he is. Making him a human took away this level of innocence, with a sexually active Castiel coming across as more than a little weird. Mostly, though, it was because of how he was treated by the Winchesters during this time that fans hated this story.
The human Castiel was kicked out from the bunker by Dean and wasn’t helped at all when he got a lame job, a joke that overstayed its welcome. The constant dilly dallying over him getting temporary angel graces were a bore as well, and fans generally overlook this period when recalling the series’ highlights.
Lucifer's Plans To Kill Jack
This became a storyline through a retcon of sorts. The overall arc had to do with Lucifer being excited to be a father and his attempts to locate Jack. When he did get to him, though, Lucifer almost instantly stole Jack’s grace and claimed he wanted to be all-powerful.
Fans generally despise this angle since it does a U-turn on Lucifer’s character development, due to which the entire storyline goes lambasted now. It also feels like an insult to those who closely followed this arc, as it ended in a generic “villain wants power” plot.
Sam Marrying Becky
Becky happens to be one of the most disliked characters the show has presented. While her obsession with Sam was always uncomfortable, she made it worse by enchanting Sam and getting him to marry her.
The show tried to play it for laughs, but fans saw it in a different way, which resulted in more hatred toward Becky. After all, forcing Sam to fall in love was bad enough, but making him marry her made both Becky and this storyline far too unhealthy for anyone’s liking.
Alternate Michael's Possession Of Dean
Fans hate it whenever the brothers are apart from one another, so one of the reasons for this story to be hated is clear. The main reason, however, is the awful execution of Alternate Michael’s possession of Dean.
Rather than show any outright acts of evil, the storyline simply had Dean trapping Michael in his head and keep worrying about it. After heavily teasing Michael’s plans for Dean, and delivering absolutely none of it, pretty much the entire first half of Season 14 was wasted on this arc.
Dean And Amara's "Love" Story
There are characters fans want Dean to have a romance with, yet they’re not crazy about his association with Amara. This played out when The Darkness was looking to end all existence, with only her affection for Dean stopping her.
However, this romance of sorts never gathered steam due to a clear reluctance from Dean, and due to a very weak explanation for their attraction. It was also weird for most to see Amara, the first being in existence, be in love with a human.
Mary And Alternate Bobby's Romance
Mary’s considered to be the worst member of the Winchester family because of the lack of interest she showed in her sons. One of the ways this manifested was her sudden romance with the alternate universe Bobby Singer, who was nothing like the main version everybody loved.
With this romance, Mary once again neglected Dean and Sam, to the point where she went off far away to be with Bobby and maintained little with her sons. There was also the matter of these two having no chemistry, as well as the fanbase’s reluctance to accept Mary with anyone else other than John.
The Campbell Family Storyline
It’s dubious as to how smart Samuel was, although there’s no doubt that next no one liked him and his family. Season 6 had the maternal side of Sam and Dean’s family in focus, none of whom displayed any real connection with the heroes.
This led to boring episodes where the Campbells did nothing more than talk about how they were family, only to keep Dean in the dark while being clueless over what to do with Soulless Sam. The only fun thing about this storyline was watching the creative ways the family were eventually killed.
Castiel Becoming The Villain
The sixth season is usually the least favorite among fans, mostly because it featured Castiel as the villain. Here, he started out with plans to avert the apocalypse, but the harsh treatment from Sam, Bobby, and Dean over his methods led to Castiel absorbing the souls from Purgatory and becoming deluded with his newfound powers.
All this was very much out of character for Castiel, who’s known for his strict morality and faithfulness to others. The fact that his friends alienated him despite Castiel’s good intentions is another sour note for fans.
Supernatural Bloodlines
This attempt at creating a spin-off resulted in the most lackluster storyline the show’s ever made. Here, Dean and Sam were barely seen at all, with focus on monsters around Chicago. The problem was that there weren’t any interesting characters to begin with.
Another major fiasco was the confusing story, where characters kept switching alliances and romances without explanation. The hook for fans had to do with Ennis, the intended lead, figuring out how his father was still alive, yet this came across as a lame attempt at fleshing out a backstory that had no chance to become interesting. All in all, Supernatural Bloodlines is ed as a rather backhanded way of using viewers to tune in to a poorly written story.