The hatred born from three hundred years of slavery and oppression was not easy to erase.
Freeing the enslaved men and giving them equal rights and opportunities as witches was no different from putting a dagger in the free men's hands.
If the matter wasn't handled carefully, the free men could stab the witches in the back.
Nevertheless, the number of men who actually bore deep-rooted hatred for witches should be a minority among the group of enslaved men. After all, many men had lost their own will when all they had known their entire lives was to obey the witches.
The absolute authority of witches was ingrained in the minds of many men living within the seven witch kingdoms. They were turned into simple-minded men due to their upbringing. As such, they were already plenty content with what they received and didn't greed for what they could get.
However, such simple-minded men were also the easiest to manipulate.