Thematically the idea is that he is destroying these creatures in self defense. If it is not justified self defense, he gets exiled (a.k.a. punished). If you compare this to 5 or 6 cost sweepers, this card is almost always better, unless your opponent is using some kind of token deck that makes tons of little creatures. Fateful Absence is 1W, instant, destroy target creature or Planeswalker, it's controller investigates. This is like casting Fateful Absence 3 times for 1 less mana and 2 fewer cards, and your opponent gets no clue tokens. And you get a 2/4 with lifelink most of the time.