Art is both objective and subjective. There is a definitive right way to go about the technical creation of a piece. Grammer, conventions, and industry practices all have a right and wrong way to go about them. Sometimes you can get away with breaking a rule but, generally, you just look like a right jerk. The subject-matter and theming are where it gets subjective. Once a piece leaves the writer's desk, they lose ownership of the theme and the message of the piece will be decided by the reader. (Hence, why themes and critical analysis are complete bullcrap according to Salinger.) If a writer crams nothing but their gospel or writes from a specific theme rather than emotional response, their piece stops being subjective art and is now just a tool of conversion. These will also get a writer declined since editors want literature, not a call to apostasy.
Write pieces for both the audience and yourself as catharsis, not exclusively for one or the other, and not to be preachy. In essence, don't be bad. - Cheers.