I see Wincest for all the reasons you mentioned, but I also see Dean/Cas - especially in the series. (Though I prefer Wincest of Dean/Cas in fanfic.)
Dean, IMHO, is a bisexual in the closet. His reactions to gay characters (denial and confusion, but not judgemental) point towards someone who overcompensates, and he is so smitten with Dr. Sexy.
Dean, IMHO, is a bisexual in the closet. His reactions to gay characters (denial and confusion, but not judgemental) point towards someone who overcompensates, and he is so smitten with Dr. Sexy.