Doctor Who is not an economist

I noticed an interesting little exchange of dialogue on Doctor Who this evening. The Doctor and Donna had just found out that a race called the Ood were in fact the slaves of humans in the 42nd (I think) century. When Donna expressed shock the Doctor suggested it was not so different an arrangement from that of our own times, asking Donna who made her clothes.

The writer probably intended to be outrageous, but I think that equating the manufacture of clothes in (for example) East Asia with slavery is really so empty-headed that it is worth hoisting a flag of protest. Is it really necessary to point out that people are not in general forced to work in clothes manufacturing: they do so because even though the work may be uncongenial and require long hours in insalubrious settings, the alternatives open to them, such as working the land, are worse? Is it really necessary to point out that multinationals obviously source from such countries partly because labour costs are lower than elsewhere, but that they would be unable to find staff except by offering pay and conditions which are at least as good and probably better than the local alternatives? Is it really necessary to point out that even if the people who make clothes are poorer than the people who buy them, both parties are better off than if the transaction had never taken place at all?