I wanted it to be useful in general not only in tribal. A board clear with a body is pretty powerful though, that's why it creates the 1/5s, if your opponent has 3 creatures, they'll still have 3 creatures, only they'll be 1/5s must attack.

But yeah, token spammers can maybe abuse it xD though zombies is the only one I can currently think of and they wouldn't want this card.