Wincest is almost canon. Brothers are gay in every single episode in first couple of seasons, until Destiel showed up. Who do you think wrote all those episodes? Eric Kripke did. Who made Sam and Dean look like some gay married couple? Kripke did. Who ships Wincest more than any of us? Kripke does. He was the one who invented Wincest!! Just like he invented Destiel, and he's also a biggest Destiel shipper than any of the Destiel fans.