Everyone is saying that they are open to discuss this, but as soon as someone says what they think about the paper they are met with dismissal. People interpret his large focus on the biological traits of women, by presenting those traits as the primary cause of the gender gap and without showing causality between those traits and the gender gap as disrespectful. Because it suggests that women are primarily at fault. That he inserted a few disclaimers and tries to avoid responsibility by saying things like "possible" doesn't really make things better but further the feeling that he didn't really care to what degree it was true.