Yes, calling Gaiman "a writer" makes sense, since, even in the art forms that involve some graphical side (comic books, TV) his role usually revolves around WRI

Yes, calling Gaiman "a writer" makes sense, since, even in the art forms that involve some graphical side (comic books, TV) his role usually revolves around WRITING the story. Someone else draws the comics, someone else films the TV shows. Gaiman's main skill is writing stories, not drawing, or acting, or directing.