The History Channel has a great history of homophobia in the comic book industry.
It reads in part:
From 1954 to 1989, mainstream U.S. comic books had rules against portraying LGBT characters, enforced by the organization known as the Comics Code Authority. The Code, as it was often simply called, was not technically government censorship, as it was a private organization and publishers were not legally bound to follow its decisions.
But newsstands and shops weren’t going to risk carrying a comic book without the Code’s approval any more than large commercial movie theaters are anxious to show films that don’t have some rating and approval from the MPAA. Because of this, mainstream comic stories were restricted for decades, and it wasn’t until 1989 that a gay, bi, queer or transgender superhero was allowed to openly appear in mainstream American comic books produced by companies such as Marvel and DC.
The American comic book industry began in the 1930s and the superhero genre truly took off after Superman’s debut in “Action Comics #1” in 1938. Following WWII, superheroes fell out of popularity and by the 1950s most had vanished, to be revived or reimagined in later years when the Atomic Age and the Space Race inspired new imagined threats and horizons. The U.S. began to experience a newfound fear of communism and anything that threatened “traditional American values.”