Because usually when they reboot it’s very poorly planned and they don’t tell writers far enough in advance. That’s why the New 52 was so confusing with Green Lantern and Batman continuing their pre-reboot storylines while there was a brand new superman, brand new Wonder Woman, etc. If they gave a writer like two years to conclude the story of Batman before a reboot that would be cool, but will never happen because comic book publishing houses are run by petty, nepotistic hacks.
Because usually when they reboot it’s very poorly planned and they don’t tell writers far enough in advance. That’s why the New 52 was so confusing with Green Lantern and Batman continuing their pre-reboot storylines while there was a brand new superman, brand new Wonder Woman, etc. If they gave a writer like two years to conclude the story of Batman before a reboot that would be cool, but will never happen because comic book publishing houses are run by petty, nepotistic hacks.