Critiquers should be concerned about how authors execute their vision, not about what they're writing about. When focusing on how, we can focus on the effectiveness of writing. Does the reader get engrossed, get carried away? That's what authors want. That's what readers want, too. :)
Furthermore, each author should write about what they are passionate about. Each author should follow their muse. Each author has their own unique path, experiences, and imagination--make use of them! As an editor, I've often found a story written about something I'd never before considered. Editors love that! I think readers love it, as well.
Good luck creating what you want effectively!