On the catlike reflexes tactics talent card, it says to exhaust the card to add two fortune dice to agility test or add two misfortune to a dodge. Why would any on want that?

It means the active defence 'Dodge' which adds difficulty to an opponent trying to hit you. So the Misfortune goes to your opponent's pool.

Yup. Giving an opponent's dice pool [bBBB] or <P> [bB] when they're trying to hit you is pretty sweet.