There was always a certain template that Supernatural followed in its storytelling, which included its own list of strengths and weaknesses. Over time, the series got into the habit of making several mistakes in its presentation, and the final season ended up repeating these rather than fixing them.
Although Sam and Dean Winchester’s last adventure took a happy ending when the brothers were reunited in Heaven, the journey to get there was paved with shoddy elements that were carried forward from the previous fourteen seasons. Had these been avoided, season 15 of Supernatural may well have been worthy of being the best in the show’s decade-and-half stay on television.
Making The Winchesters Out To Be Villains At Various Points
Later seasons of Supernatural tended to botch giving the Winchesters morally challenging situations by ending up making them the villains in certain scenarios. These include their decision to leave their own brother Adam in Hell and attempting to kill Crowley when the latter only tried to help them.
Season 15 repeated this problem by once again inadvertently making the designated villains seem good. The most striking example is when Jack was supposed to come across as a former baddie looking to redeem himself by taking his own life, yet it came across as Dean simply being a petty person refusing to forgive Jack and egging him on kill himself.
Going For Too Much Shock Value In The Finale
Every season finale has brought a twist in the end that shakes viewers enough for them to come back for the next season. However, things like season 9’s ending killing Dean off and season 12 showing the sudden death of Castiel were accused of being shocking for the sake of being so.
The series finale of Supernatural was largely well-made but divided fans due to the decision to kill off Dean permanently. This was a mistake mainly due to Dean and Sam receiving their long-overdue happy ending in the previous episode, only for this to be shattered minutes into the last episode.
Leaving Several Unanswered Questions
This was something executed by Supernatural in order to leave hooks for viewers in the long run, but certain unanswered questions were left to simmer for so long -- like leaving Adam’s fate in the cage ambiguous -- that fans weren’t all too pleased with.
Unfortunately, the final season made the most mistakes in this area, as there were many things left hanging by the end. This included not answering if Eileen married Sam, what became of the Jody Mills and her group, if Adam was returned back to life, and even what Castiel’s place in Heaven was supposed to be.
Giving Unfair Endings To Sympathic Characters
This has been a long-running issue on Supernatural, with the likes of Ellen, Jo, Benny, and many others written out of the series with an undeserved tragic ending. Season 15 repeated this mistake by bringing back several old faces but not giving them the happy ending they deserved.
This included Kevin, who was left to wander the Earth as a tortured soul, Adam, who was last seen killed off by Chuck and abandoned by his brothers, and Arthur Ketch, whose heart was ripped out when attempting to protect the Winchesters. This issue undermines the investment viewers made in these beloved characters and leaves fans hoping they get spin-offs to conclude their arcs.
Making Big Bads Too Hammy
This is a mistake that Supernatural started making starting from its sixth season where Crowley was a more humorous villain. Following this, the series indulged far too much in the hammy villain trope, making the formerly scary Lucifer out to be a jokester and pretty much every villain being too funny.
Fans hoped that season 15 would be different since God was the villain, only for Chuck to be the hammiest of all villains so far. Chuck never came across as an intimidating figure, as he was far too petty, chewed the scenery, and failed to come as a threat by his persona.
Taking Out The Villain From The Story For The Majority Of The Season
Since seasons of Supernatural ran for more than twenty episodes, the series made the decision to take the villain out for the majority of the season to stretch the story out. However, this had the side effect of making the antagonist an afterthought who suddenly appeared at the end.
Season 15’s mistake stands out more than others due to the fact that Chuck was supposed to destroy the world, yet wasted so much time that it seemed as if he wasn’t even serious. Another problem was that Chuck threw so many curveballs in his plans without actually appearing that he ended up seeming incompetent.
Rendering Crucial Plot Points Meaningless
Sam and Dean came up with more plans to fight their enemies than fans could count, but every season saw a particular plan go to waste due to the plot making them redundant. This includes plans like stopping the opening of Purgatory, only for the Leviathans to be released, as well as closing the gates of Hell and then simply deciding not to do it.
Season 15 had viewers believe that Billie and The Empty had cooked up a plan to destroy Chuck and redeem Jack, but this overarching plot went to waste when it turned out Billie simply wanted to kill everyone. This mistake has heavy consequences since it insults fans’ consumption of the story for shock value.
Sam And Castiel Failing To Stand Up To Dean
By season 7, Sam and Castiel stopped arguing with Dean and listened to his orders even if they didn’t agree with them. This progressively ruined their dynamic, as Dean essentially became their boss by the last few seasons.
Season 15 brought the opportunity for both characters to stand up to him as they wanted to help Jack while Dean wanted him killed. However, Sam and Castiel were once again shown as pushovers who had to beg Dean to change his mind rather than defy him.
Overabundance Of Comedic Moments
Although still marketed as a horror series, Supernatural indulged far too much in its comedic aspect. This started out as a good thing but eventually became a mistake when the fear factor the show once commanded was gone.
Season 15 turned this up to its highest degree with the episode surrounding Garth, showing him and Dean dancing in a bizarre comedic skit. Since this was the finale season, things needed to be much more serious, but the show went the other way with the effect being that the stakes felt significantly lowered.
Bringing Deus Ex Machina Solutions
Most of the later seasons had the heroes win out of nowhere by some incredible stroke of luck or an empowered being. This includes season 4 where Sam became powerful enough to kill a demon on his own and season 14 where Alternate Michael just happened to be there for Dean to give his consent to share his body and fight Lucifer.
Rather than develop the story and characters in such a way that their mode of victory made sense, the final season gave a weak explanation that Jack could somehow absorb the energy that Chuck released when beating the Winchesters up to become the new God and fix everything.