What special quality do "western" countries have that makes it a moral obligation to purchase from them over others? Why is it a moral good to keep value from the others?
Purchasing products made under autocratic regimes strengthens those regimes and gives them more power on the world stage.
I think "moral obligation" (a phrase the GP did not use, for the record) is a bit over the top, though.
[1]: Why are these countries “autocracies”? To better resist foreign intervention.