Another factor that kryptonite sucks is that the best/most entertaining fight scenes out of all five superman movies were:
1. Superman versus Zod and Co. in SUPERMAN 2
2. Superman versus Evil Superman in SUPERMAN 3
We gotta have Darkseid, Brainiac, Parasite, Metallo, or Bizarro for the next movie. Superman is an alien - these movies don't need to be so Earth grounded-only. Singer feels he has to keep everything so real. A good screenwriter can make a movie relatable with important relationship themes or keep things real even when dealing with other planets or aliens.