Or since thinking outside the box was earlier clamored for, how about this: people realize that Batman is sort of a derivative character with no special powers and the gap WIDENS between Action 1 and Detective 27?
Batman is iconic enough, sure, but basically was a mish-mash of pulp characters of the day, while Superman is THE discontinuity and THE true spark to the powder keg that are comics (while, superhero comics).
And you did see those hundred or so covers, splashes and adventures which feature oversized cash registers and typewriters, right? And Rainbow Batman, Zebra Batman, Lucky Charms Batman...
(p.s. I know this should probably be posted in the unpopular opinions thread!)