I've seen people post similar comments at the anon memes. I ignore those people. As long as you're polite I don't see why it hurts to ask. And many of the authors I talk to, do want to know what readers want and what prevents readers from reading their fic. I think it's weird for an author to spend all that time and effort in writing their story, finding someone to beta read it, and then not care if the presentation/format of the story drives readers away.