I think you're right. Most writers don't sit down with an agenda. But readers sometimes perceive one, because of the cognitive dissonance between their expectations and the book. They ascribe that to deliberate action by the writer (g the number of female writers who are labelled either 'feminist' (in a negative way, or 'Mary-Sue'. The reader is unused to seeing women at the centre of the story and sees it as a threat to their comfort.