I suppose, when I think about it, I don't really know anything about who tends to be written as dominant in most fandoms and why, because most of the time I don't read smut. The Supernatural fandom, however, is unavoidably full of smut; many of the fics may be amazing and gigantic and plotty, but you can bet with reasonable confidence that at some point in any given Supernatural fic there's going to be a graphic sex scene. So I've never noticed top/bottom roles before, and now that I've come across them I suppose they're not really what I expected.

Don't mind me; I'm just thinking aloud. (Also: there is nothing nothing nothing that Dean wouldn't do for Sam - so true.)

And thank you for the links! The poll and the responses to it are indeed most illuminating, and that ficlet is rather brilliant.