Comic books are a form of art, and art is political. Any form of art is an attempt by the artist to communicate imaginative ideas. These ideas, no matter if they are idealistic, futuristic, or dystopian, are based on values and beliefs. Thus, it is impossible for comics to be apolitical because being apolitical means reinforcing the status quo--a political statement in itself.
Take Captain America #1, for example. On the cover of this book, the superhero is depicted punching Hitler in the face. While this image can be seen as apolitical and relatively uncontroversial today, at the time it was extremely controversial. In March of 1941, the United States had yet to enter World War II. Adolf Hitler was a powerful world leader with an immense following. Even in the United States, there were a significant number of Nazi sympathizers. For example, a group of 20,000 sympathizers, called the German American Bund, gathered in Madison Square Garden in 1939.
At the time of the comic's publication, Hitler was not the villainous political figure that he is widely known as today.
Further, Jack Kirby, one of Captain America's creators, was Jewish.
When you take all of these factors into account, this comic is the definition of political and highly controversial. Yet, not only was the comic book financially successful, so was the character.
Thus, comic books should be political. They not only give creators like Kirby an outlet to express their political beliefs in an artistic manner, comics with a strong political undertone can also be financially successful. Comics are an art form that are created by people who have values and beliefs. Their work is bound to reflect these values and beliefs.