Perhaps it's not, for humans. For us it's just the way things are...the way they have to be. Smacking someone and not wanting to deal with them again is a more platonic kind of hate for us...kismesis is really someone you hate too much to want them dead. Usually it stems from some form of rivallry but it can strike in some pretty unusual situations.

Anyway, I guess the best I can suggest is to remember than for us, our romances are based on one emotion and that's it. It's pity or hate. Not to say it doesn't get confused sometimes because it does. But you have to just accept that they're two very different feelings alltogether and that just because a troll has a kismesis, that doesn't - or shouldn't - affect their feelings of pity for their matesprit.