1. Whether authors are responsible for defending their choices to portray races/gender/associated violence.
2. Whether authors are responsible for consequences of portraying races/gender/associated violence.
To me, these are very different. One has any merit only among readers, who basically care about the worldbuilding and the "why"s of sexism/racism being consistent. The other has social implications beyond the book. In the vein of: do violent games cause real-life violence? Does sexism portrayed in media cause/sustain sexism in real life?
Am I off here?
In the former, it's a question of saying something new, or using these defaults to tell an interesting story.
What's hard is not every reader is looking for the same thing. People have criticized Rothfuss for having too modern of a setting for example.
I think in the latter case it's readers and possibly writers who don't necessarily have a genuine grasp on actual history, and instead only a perception of history they got from their highschool and maybe college courses.
So it contributes to a false story. Does it always have RL effects? Possibly, I'm sure gender essentialism does. Another case might be one's perception of Islam and political options, as in someone trotting out the "Muslims will never be at peace with us" line.