The garleans methods aren't even that much different then some of the city states. Look at uldah for example, they enslaved the gigas and kept them in mines their entire lives. When they rightfully rebelled the collapsed the mines ontop of them to get rid of them. It's not like things have ever changed either the people in charge of Uldah are just a different kind of evil. They only love money and will do anything to get it even neglect others to the point of death. The empress is the only one who thinks differently.