Would you use the same reasoning when selling American products in foreign markets? Folks from poor countries struggle with lack of facilities/nutrition and try to produce some stuff in competition with those with better facilities/lives from US and have to compete in the same marketplace head-on. Both of them have advantages/disadvantages but one group has the strength to push others in the form of trade rules. So why should we have free trade in the form of goods but not in the form of labor?