Superman and Batman mother’s both have the same name, has any writer of these comics ever discussed the reason for this or is it just chance?
There's several possible reasons
- Martha was a very popular name for girls and women at the time
- The characters needed to be generic (so as not to upstage their famous sons), yet relatable. Picking a common woman's name made these women likely remind readers of their own mothers, or women they knew.
- Martha was considered a patriotic name due to the first First-Lady of the United States (remember, both launched around the time World War II was starting). Superman at the time was fairly patriotic (and that was before he was all in). Batman has never been terribly patriotic (modern works notwithstanding), but with other emerging comics waving the flag proudly, this would have been an easy way to make sure people knew Batman wasn't raised by (or would promulgate the ideas of) one of those people.