Wincest is not about brothers fucking. It’s about two people who cannot live without each other. Who were always meant to be and will always be everything to the other.
Sam and Dean are soul mates, and when everyone else in their life is gone, they will be alone with each other. Forever. They will spend their afterlife in heaven together. This is canon.
Sam and Dean have not been able to manage a healthy relationship with other people because of their love for each other, because NOBODY who is truly in love with either of them would want to be their second choice. As much as people try to argue the contrary, when you love someone, they are your family. You should not be able to or have to choose between the person you spend the rest of your life with and your blood family. And make no mistake, Sam and Dean will always pick each other over anyone.
The thing about them is that I think some love transcends social barriers. It is an especially complicated love that is prioritized before everything else. You don’t need to bang somebody to know that there just isn’t a place for a romantic partner as long as you have them, and your friends and family all come bottom second to them.
Sam and Dean aren’t just brothers or friends or lovers or anything. The lines all blur together with them. They are two halves that come together to make one whole person. They will never be complete apart.
So yes, if you want to see them as lovers, that’s your call. I personally love reading the fic but I know it will never happen on screen. I’m okay with that because their bond is not about that for me. Wincest is just a name. Don’t miss out on this amazing relationship because you are hung up on a word.
No, I don’t support/condone incest in real life, if that’s what you meant. Far from it actually, because ‘surprisingly’ despite having an OTP most people can’t/don’t want to understand, I’m still just another normal human being and I’m perfectly capable of separating fiction from reality :)
Hope my answer is satisfying. Have a nice day~! ;)