This is simply an improved version of colonization - rich countries extracting resources from the poor. Only now, the rich countries don't have to bother with t

This is simply an improved version of colonization - rich countries extracting resources from the poor. Only now, the rich countries don't have to bother with the maintenance of the poor countries - they just drain the valuable citizens and leave the rest. As to what you, or Canada, owe your home country - this is a nonsense question. Either there are moral obligations between people or there aren't. If there are, then the rich taking from the poor (Canada importing professionals) or the relatively well off abandoning their poor countrymen (professionals departing their homeland for better lives in rich countries) are likely failing those moral obligations. If there are no moral obligations you owe nothing but neither is anyone else obliged to not point out the resource extraction.