If there were justice in the world...

... Then anyone who babbled about how slavery* "wasn't that bad", would IMMEDIATELY be abducted and sold to a third world sweatshop, chained to a sewing machine, fed maggoty gruel, and beaten daily. Five years later, they would be asked if they still felt the same.

Edit: Slavery of the near modern, New World variety. In an ancient context where slaves really _weren't_ any worse off than free peasants, this doesn't apply.