system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What does Batman have against Superman?

I've just watched the trailer on the front page and I am none-the-wiser. You'd think Batman and Superman would be good friends, what with them both working to protect the world and all that. However, they seem to be at loggerheads.

Would someone explain what their beef is?

Edit: I've been down-voted in less than a second. This isn't a joke post. I genuinely want to know why Batman and Superman have issues.

Edit edit: Thankyou everyone for your answers! Bonus question: who is Zod?? 

Edit edit edit: for my money, the trailer wasn't so great :(.
gpt
He saw Superman fighting Zod with no concern about the destruction they were causing, killing thousands of people. As seen in the trailer, he was holding that little girl amidst all that rubble.  
  
In shows like DBZ, the good characters always demand to fight away from populated areas.
  
Nothing to do with this post, but that trailer is fantastic.