They actually tried that in 5x19, but fandom agreed that was pretty much an unmitigated disaster of fail proportions all around. Fandom was not overreacting that time. I was disappointed, but I guess not surprised.

OMG ARE YOU KIDDING?!? DEAN IS FOR SAAAAAMMMMM ALWAYS FOR SAAAAAAAMMMMM. And I will continue to believe that if it weren't for shipping politics, Sam/Cas would actually have been one of the biggest ships to come out of S4.