Maureen Mooney asks this question in her Book Report article entitled, "Graphic Novels: How They Can Work in Libraries." Here are a few responses:
Francisca Goldsmith's Booklist article states, "Teens who are exposed to these types of materials will be better able to develop critical thinking skills. Some reluctant readers will gladly pick up a graphic novel over a typical novel, and since the illustrations support the text, graphic novels also help encourage literacy."
Stephen Weiner writes, "it is possible to build a credible graphic novel collection that does not focus on violence and sexual exploitation."
Maureen Mooney insists that you "create or update your selection policy to include graphic novels before any challenges arise from the community."
Take a look at the James Solomon Russell Junior High School Library collection development policy to see how graphic novels are included.