5. The Outsiders
To show just how much Batman doesn't belong in the Justice League, the proof is in the fact that (at one time) he actually left the Justice League and started another superhero team called The Outsiders. The Outsiders are heroes who aren't considered "mainstream" and don't exhibit the squeaky clean, All-American look the JL does. Sounds perfect for Batman, right? Wrong. Because Batman doesn't play by the rules, he plays by his
own rules. It goes that he withheld some information from the rest of the Outsiders and they weren't really happy being kept out of the loop especially since the T in teamwork stands for trust. But Batman goes by one motto: In Batman, he trusts. After that fiasco, Batman disbanded the Outsiders and went back to the JL. How much of a problem is Batman if he leaves one superhero group to start another one only to disband it and return to the one that he abandoned? Either Bruce is extremely narcissistic and doesn't care about anyone's opinion or he's... extremely narcissistic and thinks he's right all the time, and doesn't care about anyone's opinion.