[Baalz]

The thing about misfortune, in my mind, is it's a constant push towards toppling you over. As long as you're on solid footing the bad events are easy enough to push back, but once you are in an earnest fight that steady push makes it a lot harder to keep your feet. Barbarian attacks aren't too bad when you can quickly retake the province, but they become a huge problem when all your troops are committed to fighting a war and you keep losing provinces you can't retake right now - just when you need them the most. A lab burning down is a moderate annoyance, until it happens when you needed forgings/rituals cast from there to support the war and now you're not only out the support, you're out the research, plus the gold for the new lab (which might very well be a huge portion of your available gold for the turn if your upkeep is high). And of course, it's all fun and games until something really bad happens to your capital early on.

Conversely, in a stalemated war several of the good events can get you the momentum to tip the balance. A couple thousand gold, an extra castle, a national hero, or a bunch of gems can be huge depending on the situation. Yes, obviously some of these can happen even with misfortune scales, but, well you could also have more income by taking turmoil scales and lucking into a bunch of high population provinces around your capital, or take sloth and hope you're surrounded by mountains.

To be sure, misfortune can be a viable choice, but it's far from free points in my mind.