The Supernatural Fandom and Gender

Supernatural has a fan base that tends to mostly identify as female. Oddly enough, the vocal majority of the fanbase tends to largely concentrate around writing about gay couples which do not exist within the story and overly analyzing “subtext” that exists in their imagination concerning said couples.

Most fans that write romance themed fanfiction between characters typically tend to either write about existing relationships within their favorite story's universe; create their own original characters for said romances; or invent couples that do not exist within the universe of the story they are writing about. Members of Supernatural's fan base who write about existing romantic relationships aside from that of John and Mary Winchester or create their own original characters for romantic relationships are rare. Instead, this is a fan base that tends to invent couples that have no basis in Supernatural and claim they are “canon,” or existing within the story itself.

The vocal majority of Supernatural's fan base tends to demonize female characters in order to write gay couples together. Said fans will claim that their couple is “canon” and fail to see that the characters they are writing about are textually straight.

I have no idea why Supernatural's fan base does this, as the vast majority of said fans identify as female; most fan communities I have been involved in that are female-dominated don't have such a huge bias towards writing gay couples. Typically, the self-insert story written by a female fan is a way for her to get involved with the character she can't be with in real life. These stories exist within the Supernatural fan community, but they are rare and relatively hard to find in comparison to a story that pairs two male characters together.

Some of the textual couples that have existed in Supernatural:

1. John and Mary Winchester.  Dean and Sam's parents.  Mary's death drives John to try and gain revenge on the yellow-eyed demon that killed her; because of her, he becomes a monster hunter and deprives the family of a normal life.
2. Mary's parents, Samuel and Deanna Campbell.  They were the ones who got Mary into the monster hunting business, and Mary later on made a deal with the yellow-eyed demon to save her father's life.
3. Sam Winchester and Amelia.  Amelia was Sam's girlfriend, and they dated while Sam attempted to get his life back together.  She finds out that he's hunting monsters and that Dean is back in his life, and Sam chooses hunting monsters over her.
4. Sam Winchester and Ruby the demoness.  Ruby manipulated Sam into drinking her blood, and she got him addicted.  This addiction made him and his powers stronger, but it also had negative psychological consequences and caused him to have an extremely hard time quitting demon blood.  They snuck around behind Dean's back, but the relationship ended when Sam, again, chose hunting monsters over a woman.  Though this case may have been justified.
5. Ruby the demoness and Castiel the angel.  They have had flirtations, and Castiel kissed her once after watching a pornographic film because it was on and mistakenly thinking a kiss was a greeting.  
6. Dean Winchester and Anna the angel.  They slept together, and then Anna rediscovered that she was an angel.  She chose Heaven over him, and tried to kill his parents before they could get together.  The relationship ended with Anna's death, though at that point it couldn't really be called a relationship anymore.
7. Charlie Bradbury and Gilda the fairy.  Charlie, an avid roleplaying geek, found herself drawn into a real version of the game.  She found Gilda, and found out that the fairy was being controlled by another geek who wanted power in the real world.  Charlie saved Gilda, and while they fell in love, Gilda had to return to her dimension and will not be in Charlie's life for a while.
8. Dean Winchester and Lisa Braeden.  Lisa was Dean's girlfriend, and she and Dean lived a fairly normal life for a year until Dean took up hunting monsters again.  The relationship soon became strained, and Dean and Lisa stopped being in a relationship because Dean chose hunting monsters over her.  At the end of season 6, she was kidnapped, and she and Ben no longer remember Dean or his job.

Couples that a large majority of the Supernatural fan base tend to focus on and are not remotely close to being textual:

1. Dean and Sam Winchester. This tends to be focused on quite often due to the Winchester brothers sharing the names of Mary's parents. In the first season, the Winchester brothers were the only two main characters, so people who wanted to write romance tended to gravitate towards the idea of the brothers being “lovers” despite them having a purely sibling-like relationship.
2. Dean and Castiel the angel. Castiel has a lot of screen time, and he and Dean are close friends. Dean helped Castiel learn what it was like to have free will. Fans of this couple tend to focus on that and not Dean's heterosexuality or Castiel having no sense of personal space with Dean because he's socially awkward for an angel and doesn't always understand human behaviors.
3. Sam and Gabriel the angel. Gabriel only has a bit of screen time, and yet for some reason many fans have latched onto the idea of Sam and Gabriel being a couple. This may be due to a need to give Sam someone to date in a fanfiction that features Dean and Castiel as a couple.
4. Dean and Benny the vampire. Fans of this couple tend to focus on the two meeting in Purgatory and fighting by one another's sides. They do not focus on how Dean and Benny are both heterosexual; Benny used to have a vampire girlfriend. In addition, there is apparently the idea that Dean Winchester cannot have a male friend who doesn't want sexual relations with him. Benny doesn't have a lot of screen time, and his last major appearance involved him killing someone despite Dean being convinced that they were blood brothers and Benny would never do that. After Benny killed, Dean essentially had to tell him that their friendship was over.
5. Bobby Singer and Crowley the demon. Bobby sold his soul to Crowley. Much is made of this when Bobby acted in a moment of desperation and wouldn't have done so otherwise.

I have no conclusive reason why the fan base tends to focus on these couples instead of the textual relationships. If I did, I would likely understand Supernatural's fan community much better. Instead, I have a theory that this has something to do with gender in the show.

The fan base tends to bash, or tear apart and demonize, female characters that “threaten” their preferred couples. Because Supernatural's writers are well aware of their fan base and the fan community, female characters tend to be shoved aside in favor of the male characters. They, in some ways, pander to the base when they kill off or otherwise demean female characters. However, they have not made one of the aforementioned four couples textual, despite all the alleged subtext fans cite as examples.

The character of Jo was bashed because she had a crush on Dean. It “threatened” the preferred couples of Dean/Sam and Dean/Castiel, so Jo tended to be demonized until she died and made the ultimate sacrifice. After that, Jo was treated with respect because she was dead and had “proven herself worthy” of being a good monster hunter.

The character of Lisa was bashed because she and Dean lived together and had an apparently happy life until Dean had to hunt monsters again. Again, this was because she “threatened” a preferred gay couple, which in this case was also Dean/Sam or Dean/Castiel. Apparently, incest or dating a male angel is preferable to Dean having a stable love life and female love interest who is actually worried about him when he goes off hunting monsters.

I don't entirely understand Supernatural's fan community, but its behavior towards couples is likely due to the show's attitudes on gender...and vice versa. The show's tendency to treat women poorly unless they're “guest characters” and not recurring influences the fan base. The fan community's tendency to portray all female characters as threats to gay couples influences the show's writers. It's a vicious cycle.