I think the main reason Superhero movies require reboots is their tendency to kill the badguys in the end. When you think of comics its always about hero X battling against villian A thru F with G thru Z appearing in another comic, being assumed dead, temporarily reformed, in prison, or on the run.
Instead they are treating it like a western or bond flick where the hero spends the entire time struggling with the villain before they get into one final shoot out which ends with the villain's death. Then the hero rides into the sunset until he is required by fate to stop the next evildoer.
It almost is never the villain gets defeated and sent to jail only to escape in the future.