Maybe you meant appealed like "The power of attracting or of arousing interest"?
If yes, it's because the Bible approves of Slavery;
Both thy bondmen, and thy bondmaids, which thou shalt have, shall be of the heathen that are round about you; of them shall ye buy bondmen and bondmaids. Moreover of the children of the strangers that do sojourn among you, of them shall ye buy, and of their families that are with you, which they begat in your land: and they shall be your possession. And ye shall take them as an inheritance for your children after you, to inherit them for a possession; they shall be your bondmen for ever. Leviticus 25:44-46.
Let as many servants as are under the yoke count their own masters worthy of all honour, that the name of God and his doctrine be not blasphemed. 1 Timothy 6:1