It's probably due to the fact that I don't care much for smut (one of my kinks is asexuality, another gay relationships without anal *lol*), but I've never figured out why it would matter so much who tops/bottoms. Do I understand preferences? Definitely. Shipping Snape, I've found that I like him better as a bottom. Do I understand why to some people it seems serious business? Nope. But to each their own, I suppose.