Stories, by their nature, have some sort of conflict. Otherwise, they would be boring. Conflict, by its nature, has at least two sides. To be able to write these two sides well, the artist has to understand, deep inside, that both sides are equally human. The more he portrays the other side as human, the better the story. The less human the other side, the more flawed the story.
That puts artists on the humanistic side of most ideological battles throughout history: against racism (the other race is people, too), against slavery (slaves are people, too), for feminism (women are people, too), for the rights of children (children think and feel just like adults), against child labor, for gay rights (homosexuals are just as human), for the downtrodden, for the poor (they are just like us, only poor), against most wars (because the other side bleeds red, too, and mourns with the same pain), and against most religions (in particular, against the religions that claim its followers are ‘the chosen’ and those who are not will not get into heaven and/or are inferior in some way).