Why Bizarro? Because he's the only other Superman-like character that would make sense. Sure he's basically got Supes power set, but they can reverse all of his moves. Freeze vision, fire breath, vacuum breath, and his supermove could be instead of punching his opponent into the atmosphere he punches them down through the planet and then hits them back up.
Also who else agrees that Bizarro is just a cooler version of Superman?