The fact that the immigrants are physically dangerous was unsettling to me because of the broader parallels to reality, and for a similar reason, I really disliked the detail that people on mars cared more about politics because the survival stakes were higher. When it became clear that the author doesn’t know how incidence rates work and saw in the reviews that later details also don’t make sense,  I decided the remaining 450 pages probably wouldn’t be a good time for me.