Perhaps some do eat less meat as vlan0 suggested. Perhaps some don't change their habits, trying to cope with the mental burden.

> It was found that [slaughterhouse workers] have a higher prevalence rate of mental health issues, in particular depression and anxiety, in addition to violence-supportive attitudes. Furthermore, the workers employ a variety of both adaptive and maladaptive strategies to cope with the workplace environment and associated stressors. Finally, there is some evidence that slaughterhouse work is associated with increased crime levels. The research reviewed has shown a link between slaughterhouse work and antisocial behavior generally and sexual offending specifically.

https://journals.sagepub.com/doi/full/10.1177/15248380211030...