yes the working conditions for slaves are hard and the food is terrible (by our standards) - but they are still better than what they have back in Africa where there is little hope. At least in America, they and their families can be taught Christianity. And not all slaveowners are terrible.
Fact remains: Dubai (like Saudi Arabia and other oil-despotisms) has an excellent lifestyle for the local sheikhs and for expats who come in on big money contracts, and it's all funded by the hyper-exploited labor of the desperate. But all this is off-topic.