You are either with or against Destiel fans. Although the fandom does not wish to admit it, giving relationships such as Destiel the benefit of the doubt is what created the divisive sections. Some seem to blindly believe that Dean is as straight as a slinky, whereas others do not see beyond the platonic friendship between the angel and his best friend. Should the writers allow Destiel to become Canon?

The relationship dynamic

For this particular aspect of the show, there are drawings, stories, and Fan Fiction depicting this dynamic. This goes to show the fandom's dedication to this OTP, even if this couple is not real.

Throughout the seasons, especially in season 4 and 8, there was massive screen time dedicated to Dean and Castiel together. As characters they have been through heaven and hell (quite literally) and know each other almost as well as Sam and Dean do.

Are these speculations backed by any evidence?

On the side of the Destiel believers, there is some controversial evidence to back up their theories. It is true that Castiel rebelled several times against Heaven for the Winchesters, and maybe Dean specifically; Dean did feel a huge amount of remorse when he thought he had left Castiel behind in Heaven; and they claim each other as family. There have been some rumors about "Supernatural" script writers wanting to make Destiel canon, such as in season 7, but they ultimately decided not to.

Furthermore, it was scripted for Dean to say "I love you" to Castiel, however, Jensen Ackles decided to alter the lines to "You are family." Jensen, himself, proclaimed in several interviews and conventions that Destiel is not real, and that its idea makes him uncomfortable. Such words have angered more than a few Destiel fanatics.

Although it's rather clear that "Supernatural" will probably not feature it, should Desitel become real?

The fate of Destiel on 'Supernatural'

It should not. "Supernatural" has been, from the very start, a show about two brothers on the road hunting demons and other evil beings that roam the Earth. Changing the dynamic in such a way would not be beneficial for the characters, and would change the core philosophy of the show.

Maybe it was the constant killing of female characters and the lack of consistent ones that led fans to find other love interests for the main characters. Either way, it looks as though Destiel will remain firmly rooted in the realm of fan fiction.