I think the fact that there's so much whump in canon in this fandom attracts people like me who like that kind of thing. And it's not even that I'm a sadist in real life. I just have a thing for h/c in a fictional setting. For me, it's all about the emotional intensity.

Sometimes I shake my head at myself, because on a rational level, I know it's a terrible thing to want to see your favourite characters getting intentionally hurt -- be it physical or emotional. Then, on the other hand, (at least for me) it's probably got to do with living vicariously through fictional characters, so that I can "enjoy" the emotion without actually having to face it in real life.

And, hey, isn't that much more healthy than having to deal with this kind of shit in RL? ;-)