The only sane and rational response to a Twitter mob, or a social justice mob, is to never defend, never explain, never apologize. Once the SJW types taste blood in the water the feeding frenzy is joined and it won’t stop until complete submission.
So you can never cede an inch, even if you are wrong, as you won’t get a second chance. Zhao’s response should have been something like, “The novel is not for you, then. Don’t read it. Do something more important with your time. And screw off.”
Anything else is inviting further abuse.