"...with great power there must also come—great responsibility!"
So reads the last panel of Amazing Fantasy #15, the 1962 Marvel Comics issue that would launch Spider-Man into the popular consciousness. While Peter Parker would generally make good on that statement with his powers as a human-spider-hybrid crime fighter, he would go on to fail miserably at doing the same with his powers as a member of the media.
Both Spider-man and Superman, formative and iconic characters in their genre, pay the bills and disguise their identities by working as journalists. You can understand why their creators chose that profession for them. Superheroism and reporting would seem to share a scrappy, do-gooding, vigilante spirit. Journalism, like a super power or magic spell, can be a shortcut to effecting change—a way to take down bad guys without weapons or armies or expensive courtroom wrangling. (Also, Jerry Siegel and Joe Shuster, Superman's creators, both had backgrounds related to journalism—Siegel toiling on his student newspaper, The Torch, and Shuster delivering copies of the Toronto Daily Star.)
However, spunky photojournalists/mild-mannered-reporters also have ethical obligations that should clash with supernatural crime fighting. The media is, in theory at least, supposed to be honest. Putting on a costume, coming up with a fake name, and lying to everyone about what you really do are the opposite of that.