A writer has only one responsibility; to write a good, internally consistent story. This is, obviously, a fairly broad rule but frankly it's the only one that can apply because otherwise you get into issues of opinion and political stances. Inserting a theme into a story is rather useless (both writers seem to make a plea for authors to consciously insert themes), because theme is ultimately up to the reader. Readers will find their own meaning in a story no matter how laboriously an author works to espouse a certain viewpoint; not to say one can't write with a certain point of view in mind, but that you can only do so much and after that it's up to your readers to find whatever meaning they shall. Themes are often agreed upon by the masses, but even then it is not set in stone.