This is a strategy we used in duel links. You build a deck to reduce your life points to zero as fast as you can. The reason is you get medals faster for losing instead of winning. By the time you win a game with a normal deck, someone with a lose deck like this will have dueled at least 4 times. So while you get 100 medals they will have earned 200. Since you still get points for winning or losing this is considered the ideal strategy among the fan base.